45 results on '"A. Billiet"'
Search Results
2. A deep learning model for brain segmentation across pediatric and adult populations
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Jaime Simarro, Maria Ines Meyer, Simon Van Eyndhoven, Thanh Vân Phan, Thibo Billiet, Diana M. Sima, and Els Ortibus
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Medicine ,Science - Abstract
Abstract Automated quantification of brain tissues on MR images has greatly contributed to the diagnosis and follow-up of neurological pathologies across various life stages. However, existing solutions are specifically designed for certain age ranges, limiting their applicability in monitoring brain development from infancy to late adulthood. This retrospective study aims to develop and validate a brain segmentation model across pediatric and adult populations. First, we trained a deep learning model to segment tissues and brain structures using T1-weighted MR images from 390 patients (age range: 2–81 years) across four different datasets. Subsequently, the model was validated on a cohort of 280 patients from six distinct test datasets (age range: 4–90 years). In the initial experiment, the proposed deep learning-based pipeline, icobrain-dl, demonstrated segmentation accuracy comparable to both pediatric and adult-specific models across diverse age groups. Subsequently, we evaluated intra- and inter-scanner variability in measurements of various tissues and structures in both pediatric and adult populations computed by icobrain-dl. Results demonstrated significantly higher reproducibility compared to similar brain quantification tools, including childmetrix, FastSurfer, and the medical device icobrain v5.9 (p-value< 0.01). Finally, we explored the potential clinical applications of icobrain-dl measurements in diagnosing pediatric patients with Cerebral Visual Impairment and adult patients with Alzheimer’s Disease.
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- 2024
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3. A model of hemodialysis after acute kidney injury in rats
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J. Mallet, P.-A. Billiet, M. Scarton, N. Benichou, M. Bobot, K. Chaibi, A. Hertig, J. Hadchouel, D. Dreyfuss, S. Gaudry, and S. Placier
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Acute kidney injury ,Intensive care unit ,Renal replacement therapy ,Hemodialysis ,Adenine 0.75% ,Animal model ,Medical emergencies. Critical care. Intensive care. First aid ,RC86-88.9 - Abstract
Abstract Background Acute kidney injury (AKI) is frequent among critically ill patients. Renal replacement therapy (RRT) is often required to deal with severe complications of AKI. This technique is however associated with side effects such as hemodynamic instability and delayed renal recovery. In this study, we aimed to describe a novel model of hemodialysis in rats with AKI and depict a dialysis membrane performance. Methods Eighteen Sprague–Dawley rats received 0.75% adenine-rich diet to induce AKI. After 2 weeks, nine underwent an arterio-venous extracorporeal circulation (ECC) (ECC group) for 2 h without a dialysis membrane on the circuit and nine received a hemodialysis session (HD group) for 2 h with an ECC circuit. All rats were hemodynamically monitored, and glomerular filtration rate (GFR) was measured by transcutaneous fluorescence after the injection of FITC-Sinistrin. Blood samples were collected at different time points to assess serum creatinine and serum urea concentrations and to determine the Kt/V. Sinistrin concentration was also quantified in both plasma and dialysis effluent. Results After 2 weeks of adenine-rich diet, rats exhibited a decrease in GFR. Both serum urea and serum creatinine concentrations increased in the ECC group but remained stable in the HD group. We found no significant difference in serum creatinine and serum urea concentrations between groups. At the end of experiments, mean serum urea was 36.7 mmol/l (95%CI 19.7–46.9 mmol/l) and 23.6 mmol/l (95%CI 15.2–33.5 mmol/l) in the ECC and HD groups, respectively (p = 0.15), and mean serum creatinine concentration was 158.0 µmol/l (95%CI 108.1–191.9 µmol/l) and 114.0 µmol/l (95%CI 90.2–140.9 µmol/l) in the ECC and HD groups, respectively (p = 0.11). The Kt/V of the model was estimated at 0.23. Sinistrin quantity in the ultrafiltrate raised steadily during the dialysis session. After 2 h, the median quantity was 149.2 µg (95% CI 99.7–250.3 µg). Conclusions This hemodialysis model is an acceptable compromise between the requirement of hemodynamic tolerance which implies reducing extracorporeal blood volume (using a small dialyzer) and the demonstration that diffusion of molecules through the membrane is achieved.
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- 2023
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4. Restrictive use of Restraints and Delirium Duration in the Intensive Care Unit (R2D2-ICU): protocol for a French multicentre parallel-group open-label randomised controlled trial
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Jean-François Timsit, Damien Contou, Julien Schmidt, Carine Roy, Romain Sonneville, Lila Bouadma, Armand Mekontso Dessap, Michel Djibré, Camille Couffignal, Juliette Audibert, Pierre Jaquet, Virginie Godard, Romane Bellot, Fariza Lamara, Tchoubou Tona, Florian Sigaud, Adam Celier, Claire Bourel, Fatiha Essardy, Renaud Cornic, ABGRALL Gwenole, ARRESTIER Romain, AUDIBERT Juliette, AUGY Jean loup, BAGATE François, BAY Pierre, BEGOT Erwan, BEN SALAH Adel, BENELLI Brice, BERTI Enora, BERTIER Astrid, BEURTON Alexandra, BILLIET Pierre-Antoine, BOUADMA Lila, BOUGNAUD Joanna, BOUILLAND Anne Laure, BOUJELBEN Mohamed, BUREAU Côme, CANDILLE Clara, CARIOU Erwann, CARTEAUX Guillaume, CATANO Jenifer, CAVALEIRO Pedro, CELIER Adam, CHAFIOTTE Pierre, CIRILLO Giulia, CLERC Sébastien, CONIA Alexandre, CORDIER Charlotte, COUPRY Louis-Marie, DA SILVA Daniel, DARTEVEL Anais, DE MONTMOLLIN Etienne, DE MONTMOLLIN Nina, DE PROST Nicolas, DECAVELE Maxens, DELERIS Robin, DEMOULE Alexandre, DESNOS Cyrielle, DESSAJAN Julien, DIEMOZ Marie-Claire, DO REGO Hermann, DO VALE Julien, DRES Martin, DUFRANC Etienne, EJZENBERG Michael, ELABBADI Alexandre, FLOCH Pierre Edouard, FOSSE Quentin, FRAPARD Thomas, GAILLET Antoine, GALERNEAU Louis-Marie, GENDREAU Ségolène, GONCALVES CAVALEIRO Pedro, GONTIER Olivier, HAMROUNI Mouldi, HAUDEBOURG Anne-Fleur, HAUDEBOURG Luc, JOLLY Florian, LA MAREC Julien, LABEDADE Pascale, LAVILLEGRAND Jean-Rémi, LECRONIER Marie, LOPINTO Julien, MASI Paul, MAYAUX Julien, MENAT Sophie, MONCOMBLE Elsa, MORAWIEC Elise, NAGLE Sophie, NEMLAGHI Safaa, PICARD Benjamin, PICHON Jeremie, PLAIS Henri, RAZAZI Keyvan, RIGAULT Guillaume, SIGAUD Florian, SONNEVILLE Romain, THY Michael, TIMSIT Jean-François, TUFFET Samuel, TURPIN Matthieu, VINCENT Xavier, VOIRIOT Guillaume, WICKY Paul-Henri, and WINDSOR Camille
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Medicine - Abstract
Introduction Physical restraint (PR) is prescribed in patients receiving invasive mechanical ventilation in the intensive care unit (ICU) to avoid unplanned removal of medical devices. However, it is associated with an increased risk of delirium. We hypothesise that a restrictive use of PR, as compared with a systematic use, could reduce the duration of delirium in ICU patients receiving invasive mechanical ventilation.Methods and analysis The Restrictive use of Restraints and Delirium Duration in ICU (R2D2-ICU) study is a national multicentric, parallel-group, randomised (1:1) open-label, controlled, superiority trial, which will be conducted in 10 ICUs. A total of 422 adult patients requiring invasive mechanical ventilation for an expected duration of at least 48 hours and eligible for prescription of PR will be randomly allocated within 6 hours from intubation to either the restrictive PR use group or the systematic PR use group, until day 14, ICU discharge or death, whichever comes first. In both groups, PR will consist of the use of wrist straps. The primary endpoint will be delirium or coma-free days, defined as the number of days spent alive in the ICU without coma or delirium within the first 14 days after randomisation. Delirium will be assessed using the Confusion Assessment Method-ICU twice daily. Key secondary endpoints will encompass agitation episodes, opioid, propofol, benzodiazepine and antipsychotic drug exposure during the 14-day intervention period, along with a core outcome set of measures evaluated 90 days postrandomisation.Ethics and dissemination The R2D2-ICU study has been approved by the Comité de Protection des Personnes (CPP) ILE DE FRANCE III—PARIS (CPP19.09.06.37521) on June 10th, 2019). Participant recruitment started on 25 January 2021. Results will be published in international peer-reviewed medical journals and presented at conferences.Trial registration number NCT04273360.
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- 2024
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5. Spinal Metastases of the Vertebrae: Three Main Categories of Pain
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Ruben Van den Brande, Charlotte Billiet, Marc Peeters, and Erik Van de Kelft
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spinal metastases ,metastatic epidural spinal cord compression ,stereotactic body radiation therapy ,separation surgery ,Science - Abstract
Oncologic back pain, infection, inflammation, and trauma are the only specific etiologies of chronic low back pain (CLBP) in contrast to most patients who have non-specific CLBP. In oncologic patients developing CLBP, it is critically important to perform further investigation to exclude spinal metastases (SM).The incidence of cancer is increasing, with 15.7–30% developing SM. In the case of symptomatic SM, we can distinguish three main categories: tumor pain; mechanical pain due to instability, with or without pathologic fractures; and metastatic epidural spinal cord compression (MESCC) or radicular compression. Treatment of SM-related pain is dependent on these categories and consists of symptomatic treatment, target therapy to the bone, radiotherapy, systemic oncologic treatment, and surgery. The care for SM is a multidisciplinary concern, with rapid evolutions in all specialties involved. It is of primordial importance to incorporate the knowledge of specialists in all participating disciplines, such as oncology, radiotherapy, and spinal surgery, to determine the adequate treatment to preserve ambulatory function and quality of life while limiting the burden of treatment if possible. Awareness of potential SM is the first and most important step in the treatment of SM-related pain. Early diagnosis and timely treatment could prevent further deterioration. In this review, we explore the pathophysiology and symptomatology of SM and the treatment options for SM-related pain: tumor pain; mechanical pain due to instability, with or without pathologic fractures; and MESCC or radicular compression.
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- 2024
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6. Association between competencies of biopsychosocial approach and job satisfaction of rehabilitation professionals in Ukraine
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Aija Klavina, Kwok Ng, Olena Lazarieva, Marina Mruga, Kateryna Tymruk-Skoropad, Serhii Rokutov, Oleh Bazylchuk, Nataliia Zakaliak, Lorenzo Billiet, Lubov Tsizh, Dariya Popovych, Kateryna Myndziv, and Olha Yezhova
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Biopsychosocial Approach ,Job Satisfaction ,Rehabilitation ,Ukraine ,Public aspects of medicine ,RA1-1270 - Abstract
Abstract Background The Biopsychosocial (BPS) model is recognized and widely accepted in the field of health care, particularly in rehabilitation. However, in clinical practice the applicability of the BPS model is a challenge for many professionals. Method This study aimed to explore the factors that impact the perception of rehabilitation professionals about the BPS model in Ukraine. In addition, the job satisfaction assessment was done to measure whether rehabilitation specialists in Ukraine fulfil their professional roles according to their expectations and values. Participants were 346 rehabilitation specialists from Ukraine who completed the Bio-Psycho-Social Scale (BPS) for Use in Healthcare and the Global Job Satisfaction Scale (GJSS). The ANOVA was used to investigate the outcome differences between the two scales. Results The highest proportion of responders in this study represented state health services. The BPS subscale outcomes on “assessment and reporting” and “professional knowledge and skills” were significantly higher for specialists from a private sector. The global job satisfaction scale outcomes did not differ between responders from the private and state health sector. The perception of professionals networks was associated with greater job satisfaction. Conclusions The findings suggest that conception of the BPS approach in rehabilitation system of Ukraine varies across the private and state settings. The professional network plays important role in job satisfaction of rehabilitation professionals in Ukraine. Future research focusing on education strategies to effectively train professionals to apply biopsychosocial approach to practice is of critical importance to prepare rehabilitation specialists in Ukraine.
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- 2022
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7. The Wiskott–Aldrich syndrome protein is required for positive selection during T-cell lineage differentiation
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Melissa Pille, John Avila, Guillem Sanchez Sanchez, Glenn Goetgeluk, Stijn De Munter, Hanne Jansen, Lore Billiet, Karin Weening, Haipeng Xue, Sarah Bonte, Joline Ingels, Laurenz De Cock, Eva Pascal, Lucas Deseins, Tessa Kerre, Tom Taghon, Georges Leclercq, David Vermijlen, Brian Davis, and Bart Vandekerckhove
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T-cell development ,Wiskott Aldrich syndrome ,T-cell repertoire ,ATO ,CRISPR/Cas9 ,INDEL ,Immunologic diseases. Allergy ,RC581-607 - Abstract
The Wiskott–Aldrich syndrome (WAS) is an X-linked primary immune deficiency caused by a mutation in the WAS gene. This leads to altered or absent WAS protein (WASp) expression and function resulting in thrombocytopenia, eczema, recurrent infections, and autoimmunity. In T cells, WASp is required for immune synapse formation. Patients with WAS show reduced numbers of peripheral blood T lymphocytes and an altered T-cell receptor repertoire. In vitro, their peripheral T cells show decreased proliferation and cytokine production upon aCD3/aCD28 stimulation. It is unclear whether these T-cell defects are acquired during peripheral activation or are, in part, generated during thymic development. Here, we assessed the role of WASp during T-cell differentiation using artificial thymic organoid cultures and in the thymus of humanized mice. Although CRISPR/Cas9 WAS knockout hematopoietic stem and progenitor cells (HSPCs) rearranged the T-cell receptor and differentiated to T-cell receptor (TCR)+ CD4+ CD8+ double-positive (DP) cells similar to wild-type HSPCs, a partial defect in the generation of CD8 single-positive (SP) cells was observed, suggesting that WASp is involved in their positive selection. TCR repertoire analysis of the DP and CD8+ SP population, however, showed a polyclonal repertoire with no bias toward autoreactivity. To our knowledge, this is the first study of the role of WASp in human T-cell differentiation and on TCR repertoire generation.
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- 2023
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8. Multi-physics DONJON5 reactor models for improved fuel cycle simulation with CLASS
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Billiet Gabriel, Doligez Xavier, Marleau Guy, Ernoult Marc, Hébert Alain, and Thiollière Nicolas
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Nuclear engineering. Atomic power ,TK9001-9401 - Abstract
This work investigates reactor model biases and their consequences in nuclear scenario simulations. Usually, the models for Pressurized Water Reactors are based on infinite 2D assembly depletion simulations, but recent work has shown the importance of 3D complete core simulation for uncertainty reduction. The consideration of a whole core leads to new reactor parameters in the simulations that may bring additional biases. The fuel temperature distribution is one of them, and previous work considered isothermal reactors, leading to probable uncertainties in spent fuel inventory at reactor discharge. To quantify those biases and their propagation in a full scenario simulation, new advanced reactor models have been developed, based on neutronics and thermal-hydraulics couplings at the core level performed with DONJON5. Results show that the plutonium isotopic quality of spent fuel is biased for an isothermal core, with values systematically higher than for multi-physics calculations. In order to propagate those discrepancies in fuel cycle simulations that involve plutonium recycling in PWR MOX fuels, the coupling between CLASS and DONJON was renewed in order to add new fuel parameters such as the fuel temperature in the core burn-up simulation. A new methodology for data interpolation from lattice calculation has been implemented that allows acceptable computational time for DONJON5 calculations that are done within the fuel cycle simulation performed by CLASS. Comparison between isothermal and multi-physics reactor models for advanced scenario simulations performed with CLASS shows that the isothermal hypothesis leads to biases up to 10% for plutonium inventory in the UOX spent fuel stockpile, comparable with biases associated with other reactor parameters such as the loading pattern.
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- 2024
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9. Precision of image-guided spinal stereotactic ablative radiotherapy and impact of positioning variables
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Charlotte Billiet, Wim Vingerhoed, Steven Van Laere, Ines Joye, Carole Mercier, Piet Dirix, Daan Nevens, Peter Vermeulen, Paul Meijnders, and Dirk Verellen
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SABR ,Spinal metastases ,Intrafraction motion ,Medical physics. Medical radiology. Nuclear medicine ,R895-920 ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Background and purpose: Spinal stereotactic ablative body radiotherapy (SABR) requires high precision. We evaluate the intrafraction motion during cone-beam computed tomography (CBCT) guided SABR with different immobilization techniques. Material and methods: Fifty-seven consecutive patients were treated for 62 spinal lesions with SABR with positioning corrected in six degrees of freedom. A surface monitoring system was used for patient set up and to ensure patient immobilization in 65% of patients. Intrafractional motion was defined as the difference between the last CBCT before the start of treatment and the first CT afterwards. Results: For all 194 fractions, the mean intrafractional motion was 0.1 cm (0–1.1 cm) in vertical direction, 0.1 cm (0–1.1 cm) in longitudinal direction and 0.1 cm (0–0.5 cm) in lateral direction. A mean pitch of 0.6° (0–4.3°), a roll of 0.5° (0–3.4°) and a rotational motion of 0.4° (0–3.9°) was observed. 95.5% of the translational errors and 95.4% of the rotational errors were within safety range. There was a significantly higher rotational motion for patients with arms along the body (p = 0.01) and without the use of the body mask (p = 0.05). For cervical locations a higher rotational motion was seen, although not significant (p = 0.1). The acquisition of an extra CBCT was correlated with a higher rotational (pitch) motion (p = 0
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- 2022
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10. Comparing treatment uncertainty for ultra- vs. standard-hypofractionated breast radiation therapy based on in-vivo dosimetry
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Yawo A.C. Fiagan, Evy Bossuyt, Melanie Machiels, Daan Nevens, Charlotte Billiet, Philip Poortmans, Thierry Gevaert, and Dirk Verellen
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Automated treatment delivery verification ,In-vivo dosimetry ,Ultrahypofractionated radiation therapy ,Early breast cancer ,Medical physics. Medical radiology. Nuclear medicine ,R895-920 ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Background and purpose: Postoperative ultrahypofractionated radiation therapy (UHFRT) in 5 fractions (fx) for breast cancer patients is as effective and safe as conventionally hypofractionated RT (HFRT) in 15 fx, liberating time for higher-level daily online Image-Guided Radiation Therapy (IGRT) corrections. In this retrospective study, treatment uncertainties occurring in patients treated with 5fx (5fx-group) were evaluated using electronic portal imaging device (EPID)-based in-vivo dosimetry (EIVD) and compared with the results from patients treated with conventionally HFRT (15fx-group) to validate the new technique and to evaluate if the shorter treatment schedule could have a positive effect on the treatment uncertainties. Materials and methods: EPID-based integrated transit dose images were acquired for each treatment fraction in the 5fx-group (203 patients) and on the first 3 days of treatment and weekly thereafter in the 15fx-group (203 patients). A total of 1015 EIVD measurements in the 5fx-group and 1144 in the 15fx-group were acquired. Of the latter group, 755 had been treated with online IGRT correction (i.e., Online-IGRT 15fx-group). Results: In the 15fx-group 12.0% of fractions failed (FFs) compared to 3.8% in the 5fx-group and 6.9% in the online-IGRT 15fx-group. Causes for FFs in the 15fx-group compared with the 5fx-group were patient positioning (7.4% vs. 2.2%), technical issues (3.1% vs. 1.2%) and breast swelling (1.4% vs. 0.5%). In the online-IGRT 15fx-group, 2.5% were attributed to patient positioning, 3.8% to technical issues and 0.5% to breast swelling. Conclusions: EIVD demonstrated that UHFRT for breast cancer results in less FFs compared to standard HFRT. A large proportion of this decrease could be explained by using daily online IGRT.
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- 2022
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11. Illumination Detection in IIIF Medieval Manuscripts Using Deep Learning
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Fouad Aouinti, Frédéric Billiet, Victoria Eyharabide, and Xavier Fresquet
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Illumination Detection ,Deep Neural Networks ,IIIF ,Medieval Studies ,Iconography ,Medieval history ,D111-203 - Abstract
Illuminated manuscripts are essential iconographic sources for medieval studies. With the massive adoption of IIIF, old and new digital collections of manuscripts are accessible online and provide interoperable image data. However, finding illuminations within the manuscripts’ pages is increasingly time consuming. This article proposes an approach based on machine learning and transfer learning that browses IIIF manuscript pages and detects the illuminated ones. To evaluate our approach, a group of domain experts created a new dataset of manually annotated IIIF manuscripts. The preliminary results show that our algorithm detects the main illuminated pages in a manuscript, thus reducing experts’ search time.
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- 2022
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12. Epidemiology of spinal metastases, metastatic epidural spinal cord compression and pathologic vertebral compression fractures in patients with solid tumors: A systematic review
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Ruben Van den Brande, Erwin MJ Cornips, Marc Peeters, Piet Ost, Charlotte Billiet, and Erik Van de Kelft
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Spinal metastases ,Metastatic epidural spinal cord compression ,Pathologic vertebral compression fracture ,Oncology ,Epidemiology ,Diseases of the musculoskeletal system ,RC925-935 ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Introduction: Spinal metastases (SM) are a frequent complication of cancer and may lead to pathologic vertebral compression fractures (pVCF) and/or metastatic epidural spinal cord compression (MESCC). Based on autopsy studies, it is estimated that about one third of all cancer patients will develop SM. These data may not provide a correct estimation of the incidence in clinical practice. Objective: This systematic review (SR) aims to provide a more accurate estimation of the incidence of SM, MESCC and pVCF in a clinical setting. Methods: We performed a SR of papers regarding epidemiology of SM, pVCF, and MESCC in patients with solid tumors conform PRISMA guidelines. A search was conducted in the PubMed and Web of Science database using the terms epidemiology, prevalence, incidence, global burden of disease, cost of disease, spinal metastas*, metastatic epidural spinal cord compression, pathologic fracture, vertebral compression fracture, vertebral metastas* and spinal neoplasms. Papers published between 1975 and august 2021 were included. Quality was evaluated by the STROBE criteria. Results: While 56 studies were included, none of them reports the actual definition used for MESCC and pVCF, inevitably introducing heterogenity. The overall cumulative incidence of SM and MESCC is 15.67% and 2.84% respectively in patients with a solid tumor. We calculated a mean cumulative incidence in patients with SM of 9.56% (95% CI 5.70%-13.42%) for MESCC and 12.63% (95% CI 7.00%-18.25%) for pVCF. Studies show an important delay between onset of symptoms and diagnosis. Conclusions: While the overall cumulative incidence for clinically diagnosed SM in patients with a solid tumor is 15.67%, autopsy studies reveal that SM are present in 30% by the time they die, suggesting underdiagnosing of SM. Approximately 1 out of 10 patients with SM will develop MESCC and another 12.6% will develop a pVCF. Understanding these epidemiologic data, should increase awareness for first symptoms, allowing early diagnosis and subsequent treatment, thus improving overall outcome.
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- 2022
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13. Improved diffusion parameter estimation by incorporating T2 relaxation properties into the DKI-FWE model
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Vincenzo Anania, Quinten Collier, Jelle Veraart, Annemieke E. Buikema, Floris Vanhevel, Thibo Billiet, Ben Jeurissen, Arnold J. den Dekker, and Jan Sijbers
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Diffusion MRI ,Partial volume effects ,Free water elimination ,Kurtosis ,DKI ,T2 relaxation ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
The free water elimination (FWE) model and its kurtosis variant (DKI-FWE) can separate tissue and free water signal contributions, thus providing tissue-specific diffusional information. However, a downside of these models is that the associated parameter estimation problem is ill-conditioned, necessitating the use of advanced estimation techniques that can potentially bias the parameter estimates. In this work, we propose the T2-DKI-FWE model that exploits the T2 relaxation properties of both compartments, thereby better conditioning the parameter estimation problem and providing, at the same time, an additional potential biomarker (the T2 of tissue). In our approach, the T2 of tissue is estimated as an unknown parameter, whereas the T2 of free water is assumed known a priori and fixed to a literature value (1573 ms). First, the error propagation of an erroneous assumption on the T2 of free water is studied. Next, the improved conditioning of T2-DKI-FWE compared to DKI-FWE is illustrated using the Cramér-Rao lower bound matrix. Finally, the performance of the T2-DKI-FWE model is compared to that of the DKI-FWE and T2-DKI models on both simulated and real datasets. The error due to a biased approximation of the T2 of free water was found to be relatively small in various diffusion metrics and for a broad range of erroneous assumptions on its underlying ground truth value. Compared to DKI-FWE, using the T2-DKI-FWE model is beneficial for the identifiability of the model parameters. Our results suggest that the T2-DKI-FWE model can achieve precise and accurate diffusion parameter estimates, through effective reduction of free water partial volume effects and by using a standard nonlinear least squares approach. In conclusion, incorporating T2 relaxation properties into the DKI-FWE model improves the conditioning of the model fitting, while only requiring an acquisition scheme with at least two different echo times.
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- 2022
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14. Social Reform International Congresses and Organizations (1846–1914): From Sources to Data
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Christophe Verbruggen, Florian Deroo, Hans Blomme, Thomas D’haeninck, Amandine Thiry, Lisa van Diem, Jan Vandersmissen, Eline Mestdagh, Bo Billiet, Judith Wolff, Sally Chambers, Pieterjan De Potter, Julie Carlier, Carmen Van Praet, Chris Leonards, and Nico Randeraad
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social reform ,transnational history ,network analysis ,social internationalism ,collective action ,History of scholarship and learning. The humanities ,AZ20-999 ,Language and Literature - Abstract
TIC-Collaborative was a collaborative digital humanities project that focused on transnational intellectual cooperation (TIC) in the long nineteenth century, in particular on transnational connections in the field of social reform. The dataset contains information on over 1650 international congresses and 450 organizations and conference series related to the social question. The project focussed on the Low Countries and a selection of reform areas.
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- 2022
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15. Outcome and toxicity of hypofractionated image-guided SABR for spinal oligometastases
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Charlotte Billiet, Ines Joye, Carole Mercier, Lieselotte Depuydt, Geert De Kerf, Peter Vermeulen, Steven Van Laere, Erik Van de Kelft, Paul Meijnders, Dirk Verellen, and Piet Dirix
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SABR ,Spinal metastases ,Outcome ,Toxicity ,Medical physics. Medical radiology. Nuclear medicine ,R895-920 ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Background: To investigate progression free survival (PFS), local control (LC) and overall survival (OS) outcomes for patients treated with spine hypofractionated stereotactic ablative radiotherapy (SABR) and to evaluate possible predictors of rapid progression in view of a correct patient selection for this potentially curative SABR. Materials and methods: A cohort of 59 patients with spinal metastases were treated with SABR. Patient selection criteria were the following: histologically proven diagnosis of a solid tumor, a World Health Organization (WHO) score ≤ 2, life expectancy > 6 months, Spinal Instability Neoplastic Score (SINS) ≤ 12 points and presenting with radically treated oligometastatic disease (≤5 lesions) or stable polymetastatic disease with an oligoprogressive lesion. Results: From March 2015 to June 2019, 59 patients were treated with Linac-based SABR to 64 spinal metastases with a median follow-up of 55 months. SABR was standard delivered every other day in 3 to 10 fractions with median prescription dose of 27 Gy (range 21–49 Gy).The 1-,2- and 5-year PFS was 98%, 85% and 75% for all patients. OS at 5 years for all patients was 92%. Metachronous lesions (p
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- 2020
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16. Stereotactic ablative body radiotherapy (SABR) combined with immunotherapy (L19-IL2) versus standard of care in stage IV NSCLC patients, ImmunoSABR: a multicentre, randomised controlled open-label phase II trial
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Relinde I. Y. Lieverse, Evert J. Van Limbergen, Cary J. G. Oberije, Esther G. C. Troost, Sine R. Hadrup, Anne-Marie C. Dingemans, Lizza E. L. Hendriks, Franziska Eckert, Crispin Hiley, Christophe Dooms, Yolande Lievens, Monique C. de Jong, Johan Bussink, Xavier Geets, Vincenzo Valentini, Giuliano Elia, Dario Neri, Charlotte Billiet, Amir Abdollahi, David Pasquier, Pierre Boisselier, Ala Yaromina, Dirk De Ruysscher, Ludwig J. Dubois, and Philippe Lambin
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Immunotherapy ,L19-IL2 ,Anti-PD-L1 ,Anti-PD-1 ,Radiotherapy ,SABR ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Abstract Background About 50% of non-small cell lung cancer (NSCLC) patients have metastatic disease at initial diagnosis, which limits their treatment options and, consequently, the 5-year survival rate (15%). Immune checkpoint inhibitors (ICI), either alone or in combination with chemotherapy, have become standard of care (SOC) for most good performance status patients. However, most patients will not obtain long-term benefit and new treatment strategies are therefore needed. We previously demonstrated clinical safety of the tumour-selective immunocytokine L19-IL2, consisting of the anti-ED-B scFv L19 antibody coupled to IL2, combined with stereotactic ablative radiotherapy (SABR). Methods This investigator-initiated, multicentric, randomised controlled open-label phase II clinical trial will test the hypothesis that the combination of SABR and L19-IL2 increases progression free survival (PFS) in patients with limited metastatic NSCLC. One hundred twenty-six patients will be stratified according to their metastatic load (oligo-metastatic: ≤5 or poly-metastatic: 6 to 10) and randomised to the experimental-arm (E-arm) or the control-arm (C-arm). The C-arm will receive SOC, according to the local protocol. E-arm oligo-metastatic patients will receive SABR to all lesions followed by L19-IL2 therapy; radiotherapy for poly-metastatic patients consists of irradiation of one (symptomatic) to a maximum of 5 lesions (including ICI in both arms if this is the SOC). The accrual period will be 2.5-years, starting after the first centre is initiated and active. Primary endpoint is PFS at 1.5-years based on blinded radiological review, and secondary endpoints are overall survival, toxicity, quality of life and abscopal response. Associative biomarker studies, immune monitoring, CT-based radiomics, stool collection, iRECIST and tumour growth rate will be performed. Discussion The combination of SABR with or without ICI and the immunocytokine L19-IL2 will be tested as 1st, 2nd or 3rd line treatment in stage IV NSCLC patients in 14 centres located in 6 countries. This bimodal and trimodal treatment approach is based on the direct cytotoxic effect of radiotherapy, the tumour selective immunocytokine L19-IL2, the abscopal effect observed distant from the irradiated metastatic site(s) and the memory effect. The first results are expected end 2023. Trial registration ImmunoSABR Protocol Code: NL67629.068.18; EudraCT: 2018–002583-11 ; Clinicaltrials.gov: NCT03705403 ; ISRCTN ID: ISRCTN49817477 ; Date of registration: 03-April-2019.
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- 2020
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17. MRI biomarkers for Alzheimer's disease: the impact of functional connectivity in the default mode network and structural connectivity between lobes on diagnostic accuracy
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R. Mohtasib, J. Alghamdi, A. Jobeir, A. Masawi, N. Pedrosa de Barros, T. Billiet, H. Struyfs, T.V. Phan, W. Van Hecke, and A. Ribbens
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Alzheimer's disease (AD) ,Icobrain ,Brain volumetry ,DTI ,DKI ,rsfMRI ,Science (General) ,Q1-390 ,Social sciences (General) ,H1-99 - Abstract
Background: At present, clinical use of MRI in Alzheimer's disease (AD) is mostly focused on the assessment of brain atrophy, namely in the hippocampal region. Despite this, multiple biomarkers reflecting structural and functional brain connectivity changes have shown promising results in the assessment of AD. To help identify the most relevant ones that may stand a chance of being used in clinical practice, we compared multiple biomarker in terms of their value to discriminate AD from healthy controls and analyzed their age dependency. Methods: 20 AD patients and 20 matched controls underwent MRI-scanning (3T GE), including T1-weighted, diffusion-MRI, and resting-state-fMRI (rsfMRI). Whole brain, white matter, gray matter, cortical gray matter and hippocampi volumes were measured using icobrain. rsfMRI between regions of the default-mode-network (DMN) was assessed using group independent-component-analysis. Median diffusivity and kurtosis were determined in gray and white-matter. DTI data was used to evaluate pairwise structural connectivity between lobar regions and the hippocampi.Logistic-Regression and Random-Forest models were trained to classify AD-status based on, respectively different isolated features and age, and feature-groups combined with age. Results: Hippocampal features, features reflecting the functional connectivity between the medial-Pre-Frontal-Cortex (mPFC) and the posterior regions of the DMN, and structural interhemispheric frontal connectivity showed the strongest differences between AD-patients and controls. Structural interhemispheric parietal connectivity, structural connectivity between the parietal lobe and hippocampus in the right hemisphere, and mPFC-DMN-features, showed only an association with AD-status (p < 0.05) but not with age. Hippocampi volumes showed an association both with age and AD-status (p < 0.05).Smallest-hippocampus-volume was the most discriminative feature. The best performance (accuracy:0.74, sensitivity:0.74, specificity:0.74) was obtained with an RF-model combining the best feature from each feature-group (smallest hippocampus volume, WM volume, median GM MD, lTPJ-mPFC connectivity and structural interhemispheric frontal connectivity) and age. Conclusions: Brain connectivity changes caused by AD are reflected in multiple MRI-biomarkers. Decline in both the functional DMN-connectivity and the parietal interhemispheric structural connectivity may assist sepparating healthy-aging driven changes from AD, complementing hippocampal volumes which are affected by both aging and AD.
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- 2022
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18. The Relationship Between (sub)national Identity, Citizenship Conceptions, and Perceived Ethnic Threat in Flanders and Wallonia for the Period 1995–2020: A Measurement Invariance Testing Strategy
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Jaak Billiet, Cecil Meeusen, and Koen Abts
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measurement invariance ,citizenship conception ,subnational identity ,perceived ethnic threat ,Belgium ,Political science - Abstract
This article examines the relationship between (sub)national identity and attitudes towards immigrants in the multinational context of Belgium. We extend our previous studies by analysing a longer time period (1995–2020) and by making a strong case for the idea that measurement invariance testing and theoretical meaningfulness are closely intertwined. To examine whether and how the relationship between (sub)national identity and perceived ethnic threat has changed over time and between regions, we first test for metric invariance of the latent concepts. Using data from the Belgian National Election Studies, we illustrate that evaluating invariance of measurements is a necessary condition for comparative research, but also that measurement equivalence testing should be considered as an empirical guide showing researchers where substantial conclusions should potentially be revisited and theoretical validity rethought. Next, we verify whether the relationship between (sub)national identity and perceptions of ethnic threat across subnational units can be attributed to different conceptions of community membership -in terms of ethnic and/or civic citizenship conceptions- in Flanders and Wallonia. While we expected that a strong identification with Flanders would primarily be related to an ethnic citizenship representation, and as a result, stronger feelings of threat towards immigrants; we expected that a strong identification with Wallonia would primarily be related to a civic representation of the nation and therefore lower feelings of threat. Thanks to our thorough invariance testing strategy, the conceptualisation and measurement of (sub)national identity had to be adjusted in Wallonia, and the hypotheses had to be qualified.
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- 2021
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19. A phase III randomized-controlled, single-blind trial to improve quality of life with stereotactic body radiotherapy for patients with painful bone metastases (ROBOMET)
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Carole Mercier, Piet Dirix, Piet Ost, Charlotte Billiet, Ines Joye, Peter Vermeulen, Yolande Lievens, and Dirk Verellen
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Stereotactic body radiotherapy ,Bone metastases ,Spinal metastases ,Pain ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Abstract Background Bone metastases represent an important source of morbidity in cancer patients, mostly due to severe pain. Radiotherapy is an established symptomatic treatment for painful bone metastases, however, when conventional techniques are used, the effectiveness is moderate. Stereotactic body radiotherapy (SBRT), delivering very high doses in a limited number of fractions in a highly conformal manner, could potentially be more effective and less toxic. Methods This is a phase III, randomized-controlled, single-blind, multicenter study evaluating the response rate of antalgic radiotherapy for painful bone metastases and the acute toxicity associated with this treatment. A total of 126 patients will be randomly assigned to receive either the standard schedule of a single fraction of 8.0 Gy delivered through three-dimensional conformal radiotherapy or a single fraction of 20.0 Gy delivered through SBRT. Primary endpoint is pain response at the treated site at 1 month after radiotherapy. Secondary endpoints are pain flare at 24–48-72 h after radiotherapy, duration of pain response, re-irradiation need, acute toxicity, late toxicity, quality of life and subsequent serious skeletal events. In a supplementary analysis, patient-compliance for a paper-and-pencil questionnaire will be compared with an electronic mode. Discussion If a dose-escalated approach within the context of single fraction stereotactic body radiotherapy could improve the pain response to radiotherapy and minimize acute toxicity, this would have an immediate impact on the quality of life for a large number of patients with advanced cancer. Potential disadvantages of this technique include increased pain flare or a higher incidence of radiation-induced fractures. Trial registration The Ethics committee of the GZA Hospitals (B099201732915) approved this study on September 4th 2018. Trial registered on Clinicaltrials.gov (NCT03831243) on February 5th 2019.
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- 2019
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20. Methylene tetrahydrofolate reductase A1298C polymorphisms influence the adult sequelae of chemotherapy in childhood-leukemia survivors.
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Iris Elens, Sabine Deprez, Thibo Billiet, Charlotte Sleurs, Veerle Labarque, Anne Uyttebroeck, Stefaan Van Gool, Jurgen Lemiere, and Rudi D'Hooge
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Medicine ,Science - Abstract
This retrospective correlation study investigated the putative link between methylene tetrahydrofolate reductase (MTHFR) A1298C mutations and chemotherapy-related brain function changes in adult childhood-leukemia survivors. To this end, we determined the relationship between the particular MTHFR1298 genotype (AA, AC or CC) of 31 adult childhood-leukemia survivors, and (1) their CSF Tau and phosphorylated Tau (pTau) levels at the time of treatment, (2) their adult performance intelligence quotient (PIQ), and (3) their regional brain connectivity using diffusion magnetic resonance imaging (dMRI) and resting-state functional MRI (rsfMRI). We confirmed that neuropathology markers Tau and pTau significantly increased in CSF of children after intrathecal methotrexate administration. Highest concentrations of these toxicity markers were found during the induction phase of the therapy. Moreover, CSF concentrations of Tau and pTau during treatment were influenced by the children's particular MTHFR1298 genotype. CSF Tau (but not pTau) levels significantly dropped after folinic acid supplementation. At adult age (on average 13.1 years since the end of their treatment), their particular MTHFR1298 genotype (AA, AC or CC) influenced the changes in PIQ and cortical connectivity that we found to be related to their childhood exposure to chemotherapeutics. In summary, we suggest that homozygous MTHFR1298CC individuals are more vulnerable to the adult sequelae of antifolate chemotherapy.
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- 2021
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21. In vitro OP9-DL1 co-culture and subsequent maturation in the presence of IL-21 generates tumor antigen-specific T cells with a favorable less-differentiated phenotype and enhanced functionality
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Sarah Bonte, Stijn de Munter, Lore Billiet, Glenn Goetgeluk, Joline Ingels, Hanne Jansen, Melissa Pille, Laurenz de Cock, Karin Weening, Tom Taghon, Georges Leclercq, Bart Vandekerckhove, and Tessa Kerre
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acute myeloid leukemia (aml) ,t cell immunotherapy ,common gamma chain cytokines ,hematopoietic stem cells ,op9-dl1 ,Immunologic diseases. Allergy ,RC581-607 ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
T cell receptor (TCR)-redirected T cells target intracellular antigens such as Wilms’ tumor 1 (WT1), a tumor-associated antigen overexpressed in several malignancies, including acute myeloid leukemia (AML). For both chimeric antigen receptor (CAR)- and TCR-redirected T cells, several clinical studies indicate that T cell subsets with a less-differentiated phenotype (e.g. stem cell memory T cells, TSCM) survive longer and mediate superior anti-tumor effects in vivo as opposed to more terminally differentiated T cells. Cytokines added during in vitro and ex vivo culture of T cells play an important role in driving the phenotype of T cells for adoptive transfer. Using the OP9-DL1 co-culture system, we have shown previously that we are able to generate in vitro, starting from clinically relevant stem cell sources, T cells with a single tumor antigen (TA)-specific TCR. This method circumvents possible TCR chain mispairing and unwanted toxicities that might occur when introducing a TA-specific TCR in peripheral blood lymphocytes. We now show that we are able to optimize our in vitro culture protocol, by adding IL-21 during maturation, resulting in generation of TA-specific T cells with a less-differentiated phenotype and enhanced in vitro anti-tumor effects. We believe the favorable TSCM-like phenotype of these in vitro generated T cells preludes superior in vivo persistence and anti-tumor efficacy. Therefore, these TA-specific T cells could be of use as a valuable new form of patient-tailored T cell immunotherapy for malignancies for which finding a suitable CAR-T target antigen is challenging, such as AML.
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- 2021
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22. A cost-utility analysis of metastasis-directed therapy for oligorecurrent prostate cancer
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E. De Bleser, R. Willems, K. Decaestecker, L. Annemans, A. De Bruycker, V. Fonteyne, N. Lumen, F. Ameye, I. Billiet, S. Joniau, G. De Meerleer, P. Ost, and R. Bultijnck
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Diseases of the genitourinary system. Urology ,RC870-923 ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Published
- 2020
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23. Harmonization of Brain Diffusion MRI: Concepts and Methods
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Maíra Siqueira Pinto, Roberto Paolella, Thibo Billiet, Pieter Van Dyck, Pieter-Jan Guns, Ben Jeurissen, Annemie Ribbens, Arnold J. den Dekker, and Jan Sijbers
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harmonization ,normalization ,diffusion MRI ,multi-site ,inter-scanner ,review ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
MRI diffusion data suffers from significant inter- and intra-site variability, which hinders multi-site and/or longitudinal diffusion studies. This variability may arise from a range of factors, such as hardware, reconstruction algorithms and acquisition settings. To allow a reliable comparison and joint analysis of diffusion data across sites and over time, there is a clear need for robust data harmonization methods. This review article provides a comprehensive overview of diffusion data harmonization concepts and methods, and their limitations. Overall, the methods for the harmonization of multi-site diffusion images can be categorized in two main groups: diffusion parametric map harmonization (DPMH) and diffusion weighted image harmonization (DWIH). Whereas DPMH harmonizes the diffusion parametric maps (e.g., FA, MD, and MK), DWIH harmonizes the diffusion-weighted images. Defining a gold standard harmonization technique for dMRI data is still an ongoing challenge. Nevertheless, in this paper we provide two classification tools, namely a feature table and a flowchart, which aim to guide the readers in selecting an appropriate harmonization method for their study.
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- 2020
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24. T-cells with a single tumor antigen-specific T-cell receptor can be generated in vitro from clinically relevant stem cell sources
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Sarah Bonte, Stijn De Munter, Glenn Goetgeluk, Joline Ingels, Melissa Pille, Lore Billiet, Tom Taghon, Georges Leclercq, Bart Vandekerckhove, and Tessa Kerre
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acute myeloid leukemia (aml) ,t-cell immunotherapy ,hematopoietic stem cells ,op9-dl1 ,Immunologic diseases. Allergy ,RC581-607 ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Chimeric antigen receptor (CAR) T-cells have shown great promise in the treatment of B-cell malignancies. For acute myeloid leukemia (AML), however, the optimal target surface antigen has yet to be discovered. Alternatively, T-cell receptor (TCR)-redirected T-cells target intracellular antigens, marking a broader territory of available target antigens. Currently, adoptive TCR T-cell therapy uses peripheral blood lymphocytes for the introduction of a transgenic TCR. However, this can cause graft-versus-host disease, due to mispairing of introduced and endogenous TCR chains. Therefore, we started from hematopoietic stem and progenitor cells (HSPC), that do not express a TCR yet, isolated from healthy donors, patients in remission after chemotherapy and AML patients at diagnosis. Using the OP9-DL1 in vitro co-culture system and agonist selection, TCR-transduced HSPC develop into mature tumor antigen-specific T-cells with only one TCR. We show here that this approach is feasible with adult HSPC from clinically relevant sources, albeit with slower maturation and lower cell yield compared to cord blood HSPC. Moreover, cryopreservation of HSPC does not have an effect on cell numbers or functionality of the generated T-cells. In conclusion, we show here that it is feasible to generate TA-specific T-cells from HSPC from adult healthy donors and patients and we believe these T-cells could be of use as a very valuable form of patient-tailored T-cell immunotherapy.
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- 2020
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25. Few-Shot Object Detection: Application to Medieval Musicological Studies
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Bekkouch Imad Eddine Ibrahim, Victoria Eyharabide, Valérie Le Page, and Frédéric Billiet
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transfer learning ,few-shot image classification ,few-shot object detection ,cultural heritage ,musical iconography ,medieval singing ,Photography ,TR1-1050 ,Computer applications to medicine. Medical informatics ,R858-859.7 ,Electronic computers. Computer science ,QA75.5-76.95 - Abstract
Detecting objects with a small representation in images is a challenging task, especially when the style of the images is very different from recent photos, which is the case for cultural heritage datasets. This problem is commonly known as few-shot object detection and is still a new field of research. This article presents a simple and effective method for black box few-shot object detection that works with all the current state-of-the-art object detection models. We also present a new dataset called MMSD for medieval musicological studies that contains five classes and 693 samples, manually annotated by a group of musicology experts. Due to the significant diversity of styles and considerable disparities between the artistic representations of the objects, our dataset is more challenging than the current standards. We evaluate our method on YOLOv4 (m/s), (Mask/Faster) RCNN, and ViT/Swin-t. We present two methods of benchmarking these models based on the overall data size and the worst-case scenario for object detection. The experimental results show that our method always improves object detector results compared to traditional transfer learning, regardless of the underlying architecture.
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- 2022
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26. Modeling Multiple-country Repeated Cross-sections. A Societal Growth Curve Model for Studying the Effect of the Economic Crisis on Perceived Ethnic Threat
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Bart Meuleman, Eldad Davidov, and Jaak Billiet
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group conflict theory ,economic vs cultural threat ,societal growth curves ,european social survey ,Social Sciences ,Statistics ,HA1-4737 - Abstract
While multiple-country repeated cross-sectional datasets are increasingly available, few cross-national studies fully exploit the richness of such data. This paper contributes to the practical knowledge on statistical analysis of cross-national time series data. For that purpose, we present a novel application of a societal growth curve model (Fairbrother, 2014) analyzing the pressing question whether the economic crisis of the past years has stirred up immigration-related threat perceptions among European citizens. Concretely, we analyze six rounds of European Social Survey data (2002-2012) to investigate whether indicators of economic downturn are systematically related to increased levels of economic and cultural threat. The societal growth curve modeling approach makes it possible to set longitudinal effects apart from cross-sectional differences and thus overcomes the weaknesses of analyses relying on single-shot cross-sectional data. Our results provide evidence that growing unemployment as well as decreasing rates of economic growth instigate feelings of economic threat. Rather than affecting citizens’ opinion uniformly, the economic crisis is found to have the strongest impact on economic threat among low educated people. While this study provides evidence that economic shocks affect concerns that immigration is bad for the economy, feelings of cultural threat are not affected by economic crises.
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- 2018
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27. Comparing longitudinal brain atrophy measurement techniques in a real-world multiple sclerosis clinical practice cohort: towards clinical integration?
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H.N. Beadnall, C. Wang, W. Van Hecke, A. Ribbens, T. Billiet, and M.H. Barnett
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Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Background: Whole brain atrophy (WBA) estimates in multiple sclerosis (MS) correlate more robustly with clinical disability than traditional, lesion-based metrics. We compare Structural Image Evaluation using Normalisation of Atrophy (SIENA) with the icobrain longitudinal pipeline (icobrain long), for assessment of longitudinal WBA in MS patients. Methods: Magnetic resonance imaging (MRI) scan pairs [1.05 (±0.15) year separation] from 102 MS patients were acquired on the same 3T scanner. Three-dimensional (3D) T1-weighted and two-dimensional (2D)/3D fluid-attenuated inversion-recovery sequences were analysed. Percentage brain volume change (PBVC) measurements were calculated using SIENA and icobrain long. Statistical correlation, agreement and consistency between methods was evaluated; MRI brain volumetric and clinical data were compared. The proportion of the cohort with annualized brain volume loss (aBVL) rates ⩾ 0.4%, ⩾0.8% and ⩾0.94% were calculated. No evidence of disease activity (NEDA) 3 and NEDA 4 were also determined. Results: Mean annualized PBVC was −0.59 (±0.65)% and −0.64 (±0.73)% as measured by icobrain long and SIENA. icobrain long and SIENA-measured annualized PBVC correlated strongly, r = 0.805 ( p < 0.001), and the agreement [intraclass correlation coefficient (ICC) 0.800] and consistency (ICC 0.801) were excellent. Weak correlations were found between MRI metrics and Expanded Disability Status Scale scores. Over half the cohort had aBVL ⩾ 0.4%, approximately a third ⩾0.8%, and aBVL was ⩾0.94% in 28.43% and 23.53% using SIENA and icobrain long, respectively. NEDA 3 was achieved in 35.29%, and NEDA 4 in 15.69% and 16.67% of the cohort, using SIENA and icobrain long to derive PBVC, respectively. Discussion: icobrain long quantified longitudinal WBA with a strong level of statistical agreement and consistency compared to SIENA in this real-world MS population. Utility of WBA measures in individuals remains challenging, but show promise as biomarkers of neurodegeneration in MS clinical practice. Optimization of MRI analysis algorithms/techniques are needed to allow reliable use in individuals. Increased levels of automation will enable more rapid clinical translation.
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- 2019
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28. Human Thymic CD10+ PD-1+ Intraepithelial Lymphocyte Precursors Acquire Interleukin-15 Responsiveness at the CD1a– CD95+ CD28– CCR7– Developmental Stage
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Lore Billiet, Glenn Goetgeluk, Sarah Bonte, Stijn De Munter, Laurenz De Cock, Melissa Pille, Joline Ingels, Hanne Jansen, Karin Weening, Filip Van Nieuwerburgh, Tessa Kerre, Tom Taghon, Georges Leclercq, and Bart Vandekerckhove
- Subjects
intraepithelial lymphocytes ,CD8αα-positive T cells ,T cell activation ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Human thymic CD8αα+ CD10+ PD-1+ αβ T cells selected through early agonist selection have been proposed as the putative thymic precursors of the human CD8αα+ intestinal intraepithelial lymphocytes (IELs). However, the progeny of these thymic precursor cells in human blood or tissues has not yet been characterized. Here, we studied the phenotypical and transcriptional differentiation of the thymic IEL precursor (IELp) lineage upon in vitro exposure to cytokines prominent in the peripheral tissues such as interleukin-15 (IL-15) and the inflammatory cytokines interleukin-12 (IL-12) and interleukin-18 (IL-18). We showed that only the CD1a− fraction of the CD10+ PD-1+ IELp population was able to proliferate with IL-15, suggesting that this subset had acquired functionality. These cells downregulated PD-1 expression and completely lost CD10 expression, whereas other surface markers such as CD95 and CXCR3 remained highly expressed. RNA-seq analysis of the IL-15-cultured cells clearly showed induction of innate-like and effector genes. Induction of the cytotoxic machinery by the CD10+ PD-1+ population was acquired in the presence of IL-15 and was further augmented by inflammatory cytokines. Our data suggest that only the CD1a− CD10+ PD-1+ population exits the thymus and survives in the periphery. Furthermore, PD-1 and CD10 expression is not an intrinsic property of this lineage, but rather characterizes a transient stage in differentiation. CD95 and CXCR3 expression combined with the absence of CD28, CCR7, and CD6 expression might be more powerful markers to define this lineage in the periphery.
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- 2020
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29. Rapid and Effective Generation of Nanobody Based CARs using PCR and Gibson Assembly
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Stijn De Munter, Alexander Van Parys, Layla Bral, Joline Ingels, Glenn Goetgeluk, Sarah Bonte, Melissa Pille, Lore Billiet, Karin Weening, Annick Verhee, Jose Van der Heyden, Tom Taghon, Georges Leclercq, Tessa Kerre, Jan Tavernier, and Bart Vandekerckhove
- Subjects
nanobody ,vhh ,chimeric antigen receptor ,car t cell ,cd33 ,cd20 ,pcr ,gibson assembly ,nanocar ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Recent approval of chimeric antigen receptor (CAR) T cell therapy by the European Medicines Agency (EMA)/Federal and Drug Administration (FDA) and the remarkable results of CAR T clinical trials illustrate the curative potential of this therapy. While CARs against a multitude of different antigens are being developed and tested (pre)clinically, there is still a need for optimization. The use of single-chain variable fragments (scFvs) as targeting moieties hampers the quick generation of functional CARs and could potentially limit the efficacy. Instead, nanobodies may largely circumvent these difficulties. We used an available nanobody library generated after immunization of llamas against Cluster of Differentiation (CD) 20 through DNA vaccination or against the ectodomain of CD33 using soluble protein. The nanobody specific sequences were amplified by PCR and cloned by Gibson Assembly into a retroviral vector containing two different second-generation CAR constructs. After transduction in T cells, we observed high cell membrane nanoCAR expression in all cases. Following stimulation of nanoCAR-expressing T cells with antigen-positive cell lines, robust T cell activation, cytokine production and tumor cell lysis both in vitro and in vivo was observed. The use of nanobody technology in combination with PCR and Gibson Assembly allows for the rapid and effective generation of compact CARs.
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- 2020
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30. Interval Coded Scoring: a toolbox for interpretable scoring systems
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Lieven Billiet, Sabine Van Huffel, and Vanya Van Belle
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Decision support ,Interpretability ,Scoring systems ,Sparse Optimization ,Classification ,Risk assessment ,Electronic computers. Computer science ,QA75.5-76.95 - Abstract
Over the last decades, clinical decision support systems have been gaining importance. They help clinicians to make effective use of the overload of available information to obtain correct diagnoses and appropriate treatments. However, their power often comes at the cost of a black box model which cannot be interpreted easily. This interpretability is of paramount importance in a medical setting with regard to trust and (legal) responsibility. In contrast, existing medical scoring systems are easy to understand and use, but they are often a simplified rule-of-thumb summary of previous medical experience rather than a well-founded system based on available data. Interval Coded Scoring (ICS) connects these two approaches, exploiting the power of sparse optimization to derive scoring systems from training data. The presented toolbox interface makes this theory easily applicable to both small and large datasets. It contains two possible problem formulations based on linear programming or elastic net. Both allow to construct a model for a binary classification problem and establish risk profiles that can be used for future diagnosis. All of this requires only a few lines of code. ICS differs from standard machine learning through its model consisting of interpretable main effects and interactions. Furthermore, insertion of expert knowledge is possible because the training can be semi-automatic. This allows end users to make a trade-off between complexity and performance based on cross-validation results and expert knowledge. Additionally, the toolbox offers an accessible way to assess classification performance via accuracy and the ROC curve, whereas the calibration of the risk profile can be evaluated via a calibration curve. Finally, the colour-coded model visualization has particular appeal if one wants to apply ICS manually on new observations, as well as for validation by experts in the specific application domains. The validity and applicability of the toolbox is demonstrated by comparing it to standard Machine Learning approaches such as Naive Bayes and Support Vector Machines for several real-life datasets. These case studies on medical problems show its applicability as a decision support system. ICS performs similarly in terms of classification and calibration. Its slightly lower performance is countered by its model simplicity which makes it the method of choice if interpretability is a key issue.
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- 2018
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31. Influence of Orientation and Radiative Heat Transfer on Aluminum Foams in Buoyancy-Induced Convection
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Marijn Billiet, Sven De Schampheleire, Henk Huisseune, and Michel De Paepe
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experimental ,heat sink ,natural convection ,metal foam ,finned heat sink ,radiation ,heat transfer ,Technology ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Microscopy ,QH201-278.5 ,Descriptive and experimental mechanics ,QC120-168.85 - Abstract
Two differently-produced open-cell aluminum foams were compared to a commercially available finned heat sink. Further, an aluminum plate and block were tested as a reference. All heat sinks have the same base plate dimensions of four by six inches. The first foam was made by investment casting of a polyurethane preform and has a porosity of 0.946 and a pore density of 10 pores per linear inch. The second foam is manufactured by casting over a solvable core and has a porosity of 0.85 and a pore density of 2.5 pores per linear inch. The effects of orientation and radiative heat transfer are experimentally investigated. The heat sinks are tested in a vertical and horizontal orientation. The effect of radiative heat transfer is investigated by comparing a painted/anodized heat sink with an untreated one. The heat flux through the heat sink for a certain temperature difference between the environment and the heat sink’s base plate is used as the performance indicator. For temperature differences larger than 30 °C, the finned heat sink outperforms the in-house-made aluminum foam heat sink on average by 17%. Furthermore, the in-house-made aluminum foam dissipates on average 12% less heat than the other aluminum foam for a temperature difference larger than 40 °C. By painting/anodizing the heat sinks, the heat transfer rate increased on average by 10% to 50%. Finally, the thermal performance of the horizontal in-house-made aluminum foam heat sink is up to 18% larger than the one of the vertical aluminum foam heat sink.
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- 2015
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32. Characterizing the microstructural basis of 'unidentified bright objects' in neurofibromatosis type 1: A combined in vivo multicomponent T2 relaxation and multi-shell diffusion MRI analysis
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Thibo Billiet, Burkhard Mädler, Felice D'Arco, Ronald Peeters, Sabine Deprez, Ellen Plasschaert, Alexander Leemans, Hui Zhang, Bea Van den Bergh, Mathieu Vandenbulcke, Eric Legius, Stefan Sunaert, and Louise Emsell
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Myelin water imaging (MWI) ,Diffusion tensor imaging (DTI) ,Diffusion kurtosis imaging (DKI) ,Neurite orientation dispersion and density imaging (NODDI) ,Neurofibromatosis type 1 (NF1) ,Unidentified bright objects (UBOs) ,Computer applications to medicine. Medical informatics ,R858-859.7 ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Introduction: The histopathological basis of “unidentified bright objects” (UBOs) (hyperintense regions seen on T2-weighted magnetic resonance (MR) brain scans in neurofibromatosis-1 (NF1)) remains unclear. New in vivo MRI-based techniques (multi-exponential T2 relaxation (MET2) and diffusion MR imaging (dMRI)) provide measures relating to microstructural change. We combined these methods and present previously unreported data on in vivo UBO microstructure in NF1. Methods: 3-Tesla dMRI data were acquired on 17 NF1 patients, covering 30 white matter UBOs. Diffusion tensor, kurtosis and neurite orientation and dispersion density imaging parameters were calculated within UBO sites and in contralateral normal appearing white matter (cNAWM). Analysis of MET2 parameters was performed on 24 UBO–cNAWM pairs. Results: No significant alterations in the myelin water fraction and intra- and extracellular (IE) water fraction were found. Mean T2 time of IE water was significantly higher in UBOs. UBOs furthermore showed increased axial, radial and mean diffusivity, and decreased fractional anisotropy, mean kurtosis and neurite density index compared to cNAWM. Neurite orientation dispersion and isotropic fluid fraction were unaltered. Conclusion: Our results suggest that demyelination and axonal degeneration are unlikely to be present in UBOs, which appear to be mainly caused by a shift towards a higher T2-value of the intra- and extracellular water pool. This may arise from altered microstructural compartmentalization, and an increase in ‘extracellular-like’, intracellular water, possibly due to intramyelinic edema. These findings confirm the added value of combining dMRI and MET2 to characterize the microstructural basis of T2 hyperintensities in vivo.
- Published
- 2014
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33. Recognition of Physical Activities from a Single Arm-Worn Accelerometer: A Multiway Approach
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Lieven Billiet, Thijs Swinnen, Kurt de Vlam, Rene Westhovens, and Sabine Van Huffel
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physical therapy ,activity recognition ,accelerometry ,tensor decomposition ,classification with rejection ,Information technology ,T58.5-58.64 - Abstract
In current clinical practice, functional limitations due to chronic musculoskeletal diseases are still being assessed subjectively, e.g., using questionnaires and function scores. Performance-based methods, on the other hand, offer objective insights. Hence, they recently attracted more interest as an additional source of information. This work offers a step towards the shift to performance-based methods by recognizing standardized activities from continuous readings using a single accelerometer mounted on a patient’s arm. The proposed procedure consists of two steps. Firstly, activities are segmented, including rejection of non-informative segments. Secondly, the segments are associated to predefined activities using a multiway pattern matching approach based on higher order discriminant analysis (HODA). The two steps are combined into a multi-layered framework. Experiments on data recorded from 39 patients with spondyloarthritis show results with a classification accuracy of 94.34% when perfect segmentation is assumed. Automatic segmentation has 89.32% overlap with this ideal scenario. However, combining both drops performance to 62.34% due to several badly-recognized subjects. Still, these results are shown to significantly outperform a more traditional pattern matching approach. Overall, the work indicates promising viability of the technique to automate recognition and, through future work, assessment, of functional capacity.
- Published
- 2018
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34. Analysis of phenotype and outcome in essential thrombocythemia with CALR or JAK2 mutations
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Carla Al Assaf, Florence Van Obbergh, Johan Billiet, Els Lierman, Timothy Devos, Carlos Graux, Anne-Sophie Hervent, Jan Emmerechts, Thomas Tousseyn, Pascale De Paepe, Petros Papadopoulos, Lucienne Michaux, and Peter Vandenberghe
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Diseases of the blood and blood-forming organs ,RC633-647.5 - Abstract
The JAK2 V617F mutation, the thrombopoietin receptor MPL W515K/L mutation and calreticulin (CALR) mutations are mutually exclusive in essential thrombocythemia and support a novel molecular categorization of essential thrombocythemia. CALR mutations account for approximately 30% of cases of essential thrombocythemia. In a retrospective study, we examined the frequency of MPL and CALR mutations in JAK2 V617F-negative cases of essential thrombocythemia (n=103). In addition, we compared the clinical phenotype and outcome of CALR mutant cases of essential thrombocythemia with a cohort of JAK2 V617F-positive essential thrombocythemia (n=57). CALR-positive cases represented 63.7% of double-negative cases of essential thrombocythemia, and most carried CALR type 1 or type 2 indels. However, we also identified one patient who was positive for both the JAK2 V617F and the CALR mutations. This study revealed that CALR mutant essential thrombocythemia is associated with younger age, higher platelet counts, lower erythrocyte counts, leukocyte counts, hemoglobin, and hematocrit, and increased risk of progression to myelofibrosis in comparison with JAK2 V617F-positive essential thrombocythemia. Analysis of the CALR mutant group according to indel type showed that CALR type 1 deletion is strongly associated with male gender. CALR mutant patients had a better overall survival than JAK2 V617F-positive patients, in particular patients of age 60 years or younger. In conclusion, this study in a Belgian cohort of patients supports and extends the growing body of evidence that CALR mutant cases of essential thrombocythemia are phenotypically distinct from JAK2 V617F-positive cases, with regards to clinical and hematologic presentation as well as overall survival.
- Published
- 2015
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35. 16S rRNA Amplicon Sequencing Demonstrates that Indoor-Reared Bumblebees (Bombus terrestris) Harbor a Core Subset of Bacteria Normally Associated with the Wild Host.
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Ivan Meeus, Laurian Parmentier, Annelies Billiet, Kevin Maebe, Filip Van Nieuwerburgh, Dieter Deforce, Felix Wäckers, Peter Vandamme, and Guy Smagghe
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Medicine ,Science - Abstract
A MiSeq multiplexed 16S rRNA amplicon sequencing of the gut microbiota of wild and indoor-reared Bombus terrestris (bumblebees) confirmed the presence of a core set of bacteria, which consisted of Neisseriaceae (Snodgrassella), Orbaceae (Gilliamella), Lactobacillaceae (Lactobacillus), and Bifidobacteriaceae (Bifidobacterium). In wild B. terrestris we detected several non-core bacteria having a more variable prevalence. Although Enterobacteriaceae are unreported by non next-generation sequencing studies, it can become a dominant gut resident. Furthermore the presence of some non-core lactobacilli were associated with the relative abundance of bifidobacteria. This association was not observed in indoor-reared bumblebees lacking the non-core bacteria, but having a more standardized microbiota compared to their wild counterparts. The impact of the bottleneck microbiota of indoor-reared bumblebees when they are used in the field for pollination purpose is discussed.
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- 2015
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36. Experimental Assessment of a Helical Coil Heat Exchanger Operating at Subcritical and Supercritical Conditions in a Small-Scale Solar Organic Rankine Cycle
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Marija Lazova, Alihan Kaya, Marijn Billiet, Steven Lecompte, Dimitris Manolakos, and Michel De Paepe
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experimental research ,helical coil heat exchanger ,organic Rankine cycle ,subcritical ,supercritical ,heat transfer ,Technology - Abstract
In this study, the performance of a helical coil heat exchanger operating at subcritical and supercritical conditions is analysed. The counter-current heat exchanger was specially designed to operate at a maximal pressure and temperature of 42 bar and 200 °C, respectively. The small-scale solar organic Rankine cycle (ORC) installation has a net power output of 3 kWe. The first tests were done in a laboratory where an electrical heater was used instead of the concentrated photovoltaic/thermal (CPV/T) collectors. The inlet heating fluid temperature of the water was 95 °C. The effects of different parameters on the heat transfer rate in the heat exchanger were investigated. Particularly, the performance analysis was elaborated considering the changes of the mass flow rate of the working fluid (R-404A) in the range of 0.20–0.33 kg/s and the inlet pressure varying from 18 bar up to 41 bar. Hence, the variation of the heat flux was in the range of 5–9 kW/m2. The results show that the working fluid’s mass flow rate has significant influence on the heat transfer rate rather than the operational pressure. Furthermore, from the comparison between the experimental results with the heat transfer correlations from the literature, the experimental results fall within the uncertainty range for the supercritical analysis but there is a deviation of the investigated subcritical correlations.
- Published
- 2017
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- View/download PDF
37. High throughput micro-well generation of hepatocyte micro-aggregates for tissue engineering.
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Elien Gevaert, Laurent Dollé, Thomas Billiet, Peter Dubruel, Leo van Grunsven, Aart van Apeldoorn, and Ria Cornelissen
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Medicine ,Science - Abstract
The main challenge in hepatic tissue engineering is the fast dedifferentiation of primary hepatocytes in vitro. One successful approach to maintain hepatocyte phenotype on the longer term is the cultivation of cells as aggregates. This paper demonstrates the use of an agarose micro-well chip for the high throughput generation of hepatocyte aggregates, uniform in size. In our study we observed that aggregation of hepatocytes had a beneficial effect on the expression of certain hepatocyte specific markers. Moreover we observed that the beneficial effect was dependent on the aggregate dimensions, indicating that aggregate parameters should be carefully considered. In a second part of the study, the selected aggregates were immobilized by encapsulation in methacrylamide-modified gelatin. Phenotype evaluations revealed that a stable hepatocyte phenotype could be maintained during 21 days when encapsulated in the hydrogel. In conclusion we have demonstrated the beneficial use of micro-well chips for hepatocyte aggregation and the size-dependent effects on hepatocyte phenotype. We also pointed out that methacrylamide-modified gelatin is suitable for the encapsulation of these aggregates.
- Published
- 2014
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38. Accelerometry-Based Activity Recognition and Assessment in Rheumatic and Musculoskeletal Diseases
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Lieven Billiet, Thijs Willem Swinnen, Rene Westhovens, Kurt de Vlam, and Sabine Van Huffel
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accelerometry ,activity capacity ,activity performance ,activity recognition ,interpretable medical scoring systems ,physical activity ,physical therapy ,monitoring ,Chemical technology ,TP1-1185 - Abstract
One of the important aspects to be considered in rheumatic and musculoskeletal diseases is the patient’s activity capacity (or performance), defined as the ability to perform a task. Currently, it is assessed by physicians or health professionals mainly by means of a patient-reported questionnaire, sometimes combined with the therapist’s judgment on performance-based tasks. This work introduces an approach to assess the activity capacity at home in a more objective, yet interpretable way. It offers a pilot study on 28 patients suffering from axial spondyloarthritis (axSpA) to demonstrate its efficacy. Firstly, a protocol is introduced to recognize a limited set of six transition activities in the home environment using a single accelerometer. To this end, a hierarchical classifier with the rejection of non-informative activity segments has been developed drawing on both direct pattern recognition and statistical signal features. Secondly, the recognized activities should be assessed, similarly to the scoring performed by patients themselves. This is achieved through the interval coded scoring (ICS) system, a novel method to extract an interpretable scoring system from data. The activity recognition reaches an average accuracy of 93.5%; assessment is currently 64.3% accurate. These results indicate the potential of the approach; a next step should be its validation in a larger patient study.
- Published
- 2016
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39. A Relational Model for the Possibilistic Valid-time Approach
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Jose Enrique Pons, Nicolás Marín, Olga Pons, Christophe Billiet, and Guy de Tré
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fuzzy ,temporal ,database ,Electronic computers. Computer science ,QA75.5-76.95 - Abstract
In real world, it is very common that some objects or concepts have properties with a time-variant or timerelated nature. Modelling this kind of objects or concepts in a (relational) database schema is possible, but time-variant and time-related attributes have an impact on the consistency of the entire database and must be appropriately managed. Therefore, temporal database models have been proposed to deal with this problem in the literature. Time can be affected by imprecision, vagueness and / or uncertainty, since existing time measuring devices are inherently imperfect. Additionally, human beings manage time using temporal indications and temporal notions, which may also be imprecise. However, the imperfection in human-used temporal indications is supported by human interpretation, whereas information systems need appropriate support in order to accomplish this task. Several proposals for dealing with such imperfections when modelling temporal data exist. Some of these proposals transform the temporal data into a compact representation but there is not a formal model for managing and handling uncertainty regarding temporal information. In this work we present a novel model to deal with imprecision in valid-time databases together with the definition and implementation of the data manipulation language, .
- Published
- 2012
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40. Measurement and adjustment of non-response bias based on non-response surveys: the case of Belgium and Norway in the European Social Survey Round 3
- Author
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Hideko Matsuo, Jaak Billiet, Geert Loosveldt, Frode Berglund, and Øyven Kleven
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non-response survey ,non-response bias ,propensity score weighting ,data quality ,Social sciences (General) ,H1-99 - Abstract
In earlier rounds of the European Social Survey, non-response bias was studied by using population statistics and call record information (para data). In the third round, a new feature was introduced: two kinds of non-respondent surveys were set up using a short list of questions which were designed to study non-response bias. In Belgium, a very short questionnaire was offered to all refusals at the doorstep (doorstep questions survey, DQS). In Norway and two other countries, somewhat longer versions of the basic questionnaire were offered to all main survey non-respondents and to samples of respondents (non-response survey, NRS). Logistic regression models were applied in order to estimate response propensities. This paper shows that propensity score weighting adjustment of non-response bias, on the basis of key socio-demographic and attitudinal variables, is effective for most demographic and non-demographic variables in both Belgium and Norway. Application of the weighting procedure balances the samples of cooperative respondents and non-respondents according to the key variables studied since systematic differences between cooperative respondents and non-respondents have disappeared.
- Published
- 2010
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41. A Monte Carlo sample size study: how many countries are needed for accurate multilevel SEM?
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Bart Meuleman and Jaak Billiet
- Subjects
multilevel SEM ,sample size ,Monte Carlo study ,cross-national research ,Social sciences (General) ,H1-99 - Abstract
Recently, there has been growing scientific interest for cross-national survey research. Various scholars have used multilevel techniques to link individual characteristics to aspects of the national context. At first sight, multilevel SEM seems to be a promising tool for this purpose, as it integrates multilevel modeling within a latent variable framework. However, due to the fact that the number of countries in most international surveys does not exceed 30, the application of multilevel SEM in cross-national research is problematic. Taking European Social Survey (ESS) data as a point of departure, this paper uses Monte Carlo studies to assess the estimation accuracy of multilevel SEM with small group sample sizes. The results indicate that a group sample size of 20 - a situation common in cross-national research - does not guarantee accurate estimation at all. Unacceptable amounts of parameter and standard error bias are present for the between-level estimates. Unless the standardized effect is very large (0.75), statistical power for detecting a significant between-level structural effect is seriously lacking. Required group sample sizes depend strongly on the specific interests of the researcher, the expected effect sizes and the complexity of the model. If the between-level model is relatively simple and one is merely interested in the between-level factor structure, a group sample size of 40 could be sufficient. To detect large (>0.50) structural effects at the between level, at least 60 groups are required. To have an acceptable probability of detecting smaller effects, more than 100 groups are needed. These guidelines are shown to be quite robust for varying cluster sizes and intra-class correlations (ICCs).
- Published
- 2009
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- View/download PDF
42. Andrew Jordan & Duncan Liefferink (2005) Environmental Policy on Europe: The Europeanization of National Environmental Policy
- Author
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Stijn Billiet, Karen Hussey, and Claudia Dias Soares
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Political science ,Social Sciences - Published
- 2007
43. A Fluorescence Tracer Based System for Automatic Identification of Doped Plastics in a Mixed Waste Stream
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Rafi Ahmad, C Rogge, and E Billiet
- Subjects
Control engineering systems. Automatic machinery (General) ,TJ212-225 ,Technology (General) ,T1-995 - Published
- 1999
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44. Designing the selenium and bladder cancer trial (SELEBLAT), a phase lll randomized chemoprevention study with selenium on recurrence of bladder cancer in Belgium
- Author
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Goossens Maria E, Buntinx Frank, Joniau Steven, Ackaert Koen, Ameye Filip, Billiet Ignace, Braeckman Johan, Breugelmans Alex, Darras Jochen, Dilen Kurt, Goeman Lieven, Kellen Eliane, Tombal Bertrand, Van Bruwaene Siska, Van Cleyenbreuge Ben, Van der Aa Frank, Vekemans Kris, Van Poppel Hendrik, and Zeegers Maurice P
- Subjects
Selenium ,Bladder cancer ,Transitional Cell Carcinoma ,Chemoprevention ,Randomized clinical trial ,Urology ,Diseases of the genitourinary system. Urology ,RC870-923 - Abstract
Abstract Background In Belgium, bladder cancer is the fifth most common cancer in males (5.2%) and the sixth most frequent cause of death from cancer in males (3.8%). Previous epidemiological studies have consistently reported that selenium concentrations were inversely associated with the risk of bladder cancer. This suggests that selenium may also be suitable for chemoprevention of recurrence. Method The SELEBLAT study opened in September 2009 and is still recruiting all patients with non-invasive transitional cell carcinoma of the bladder on TURB operation in 15 Belgian hospitals. Recruitment progress can be monitored live at http://www.seleblat.org. Patients are randomly assigned to selenium yeast (200 μg/day) supplementation for 3 years or matching placebo, in addition to standard care. The objective is to determine the effect of selenium on the recurrence of bladder cancer. Randomization is stratified by treatment centre. A computerized algorithm randomly assigns the patients to a treatment arm. All study personnel and participants are blinded to treatment assignment for the duration of the study. Design The SELEnium and BLAdder cancer Trial (SELEBLAT) is a phase III randomized, placebo-controlled, academic, double-blind superior trial. Discussion This is the first report on a selenium randomized trial in bladder cancer patients. Trial registration ClinicalTrials.gov identifier: NCT00729287
- Published
- 2012
- Full Text
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45. L'impact des oiseaux granivores sur les cultures céréalières dans le delta central du Niger au Mali
- Author
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Billiet, F.
- Subjects
Agriculture - Abstract
The impact of granivorous birds on cereal farming in the central delta of Niger river in Mali. Masses of granivorous birds destroy about 5-10 % of the rice crop produced in the central Niger delta. To the local species (ducks, ploceid birds and the quelea, which is the most abundant and noxious pest with numbers ranging from 18 million in January to 10 million in May-June) add palearctic migratory birds, which are mainly ducks and stilt-birds. Bird control is necessarily undertaken but is inefficient due to the vastness of the region, difficult access to the sites, the number of birds and insufficient financial means.
- Published
- 1983
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