26 results on '"Staelens D"'
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2. Combination of apps and open platforms with telematics solutions will improve flexibility, security and data consistency for fleets and shippers
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Staelens, D., primary
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- 2017
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3. Impact of European Driving and Resting directives on efficient planning of vehicles
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Staelens, D., primary
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- 2017
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4. Treatment patterns in elderly patients with locally advanced head and neck squamous cell carcinoma (LA-HNSCC): Results from an EORTC led survey
- Author
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Oosting, S., primary, Desideri, I., additional, Staelens, D., additional, Caballero, C., additional, Tribius, S., additional, Simon, C., additional, Singer, S., additional, Gregoire, V., additional, Fortpied, C., additional, and Luciani, A., additional
- Published
- 2018
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5. 1106P - Treatment patterns in elderly patients with locally advanced head and neck squamous cell carcinoma (LA-HNSCC): Results from an EORTC led survey
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Oosting, S., Desideri, I., Staelens, D., Caballero, C., Tribius, S., Simon, C., Singer, S., Gregoire, V., Fortpied, C., and Luciani, A.
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- 2018
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6. P033 Prevention of recurrent Clostridium difficile infection by neutralizing monoclonal antibodies in a hamster relapse model
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Staelens, D., primary, Van de Wouwer, M., additional, Brouwers, E., additional, Caluwaerts, S., additional, Rottiers, P., additional, Vanhoenacker, P., additional, Geukens, N., additional, Declerck, P.J., additional, Ferrante, M., additional, Vermeire, S., additional, Rutgeerts, P., additional, and Van Assche, G., additional
- Published
- 2014
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7. OP19 Genetic and functional evidence for a role for CYLD in Crohn's disease: Results from a European consortium
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Cleynen, I., primary, Vazeille, E., additional, Artieda, M., additional, Szczypiorska, M., additional, Bringer, M.-A., additional, Verspaget, H., additional, Lakatos, P., additional, Seibold, F., additional, Parnell, K., additional, Weersma, R., additional, Mahachie, J., additional, Morgan-Walsh, R., additional, Staelens, D., additional, Arijs, I., additional, Müller, S., additional, Tordai, A., additional, Hommes, D.W., additional, Ahmad, T., additional, Wijmenga, C., additional, Pender, S., additional, Rutgeerts, P., additional, Lottaz, D., additional, Van Steen, K., additional, Vermeire, S., additional, and Darfeuille-Michaud, A., additional
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- 2012
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8. Conformational variability of the synthetic peptide 129-141 of the mouse prion protein.
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Prévost, Martine, Jacquemotte, F, Oberg, KEITH, Staelens, D, Devreese, Bart, Van Beeumen, J, Prévost, Martine, Jacquemotte, F, Oberg, KEITH, Staelens, D, Devreese, Bart, and Van Beeumen, J
- Abstract
The effect of solution conditions on the conformation of the peptide corresponding to residues 129-141 of the mouse prion protein has been examined by experimental and theoretical tools including circular dichroism, secondary structure predictions, and Molecular Dynamics simulations. The conformational properties of the peptide observed by CD confirm the prediction results: the peptide is chiefly random coil in water. The conformational sampling performed by Molecular Dynamics simulations in water also corroborates the flexibility of the peptide, in particular for the N-terminal part. We show, however, that the peptide samples hairpin conformations in one of several approximately 1-ns Molecular Dynamics simulations in water. Interestingly, the analysis of the CD spectra obtained in this study suggests the presence of beta-structure which, given the length of the peptide, can only consist in beta-hairpin. The peptide can also be induced to form a modest percentage of helical structure in the presence of organic cosolvents such as trifluoroethanol, or detergents such as sodium dodecyl sulfate and lysophosphatidylcholine. This result is different from that obtained for a homologous hamster fragment, which differs from the mouse sequence by the single substitution of Ile 139 to Met. Interestingly, this substitution is crucial for the barrier in the transmission of the prion disease between hamsters and mice., Journal Article, Research Support, Non-U.S. Gov't, SCOPUS: ar.j, info:eu-repo/semantics/published
- Published
- 2000
9. An implementation approach for local area networks
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Janssens, G.K, primary, Raes, J, additional, and Staelens, D, additional
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- 1987
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10. Epidemiological study of phylogenetic transmission clusters in a local HIV-1 epidemic reveals distinct differences between subtype B and non-B infections
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Chalmet Kristen, Staelens Delfien, Blot Stijn, Dinakis Sylvie, Pelgrom Jolanda, Plum Jean, Vogelaers Dirk, Vandekerckhove Linos, and Verhofstede Chris
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Infectious and parasitic diseases ,RC109-216 - Abstract
Abstract Background The number of HIV-1 infected individuals in the Western world continues to rise. More in-depth understanding of regional HIV-1 epidemics is necessary for the optimal design and adequate use of future prevention strategies. The use of a combination of phylogenetic analysis of HIV sequences, with data on patients' demographics, infection route, clinical information and laboratory results, will allow a better characterization of individuals responsible for local transmission. Methods Baseline HIV-1 pol sequences, obtained through routine drug-resistance testing, from 506 patients, newly diagnosed between 2001 and 2009, were used to construct phylogenetic trees and identify transmission-clusters. Patients' demographics, laboratory and clinical data, were retrieved anonymously. Statistical analysis was performed to identify subtype-specific and transmission-cluster-specific characteristics. Results Multivariate analysis showed significant differences between the 59.7% of individuals with subtype B infection and the 40.3% non-B infected individuals, with regard to route of transmission, origin, infection with Chlamydia (p = 0.01) and infection with Hepatitis C virus (p = 0.017). More and larger transmission-clusters were identified among the subtype B infections (p < 0.001). Overall, in multivariate analysis, clustering was significantly associated with Caucasian origin, infection through homosexual contact and younger age (all p < 0.001). Bivariate analysis additionally showed a correlation between clustering and syphilis (p < 0.001), higher CD4 counts (p = 0.002), Chlamydia infection (p = 0.013) and primary HIV (p = 0.017). Conclusions Combination of phylogenetics with demographic information, laboratory and clinical data, revealed that HIV-1 subtype B infected Caucasian men-who-have-sex-with-men with high prevalence of sexually transmitted diseases, account for the majority of local HIV-transmissions. This finding elucidates observed epidemiological trends through molecular analysis, and justifies sustained focus in prevention on this high risk group.
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- 2010
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11. Reverse transcription of plasma-derived HIV-1 RNA generates multiple artifacts through tRNA(Lys-3)-priming.
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Hardy J, Demecheleer E, Schauvliege M, Staelens D, Mortier V, and Verhofstede C
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- Humans, Artifacts, DNA, Complementary genetics, Transcription, Genetic, Base Sequence, RNA, Viral genetics, RNA, Transfer genetics, Nucleic Acid Conformation, Reverse Transcription, HIV-1 genetics
- Abstract
In vitro reverse transcription of full-length HIV-1 RNA extracted from the blood plasma of people living with HIV-1 remains challenging. Here, we describe the initiation of reverse transcription of plasma-derived viral RNA in the absence of an exogenous primer. Real-time PCR and Sanger sequencing were applied to identify the source and to monitor the outcome of this reaction. Results demonstrated that during purification of viral RNA from plasma, tRNA(Lys-3) is co-extracted in a complex with the viral RNA. In the presence of a reverse transcription enzyme, this tRNA(Lys-3) can induce reverse transcription, a reaction that is not confined to transcription of the 5' end of the viral RNA. A range of cDNA products is generated, most of them indicative for the occurrence of in vitro strand transfer events that involve translocation of cDNA from the 5' end to random positions on the viral RNA. This process results in the formation of cDNAs with large internal deletions. However, near full-length cDNA and cDNA with sequence patterns resembling multiple spliced HIV-1 RNA were also detected. Despite its potential to introduce significant bias in the interpretation of results across various applications, tRNA(Lys-3)-driven reverse transcription has been overlooked thus far. A more in-depth study of this tRNA-driven in vitro reaction may provide new insight into the complex process of in vivo HIV-1 replication.IMPORTANCEThe use of silica-based extraction methods for purifying HIV-1 RNA from viral particles is a common practice, but it involves co-extraction of human tRNA(Lys-3) due to the strong interactions between these molecules. This co-extraction becomes particularly significant when the extracted RNA is used in reverse transcription reactions, as the tRNA(Lys-3) then serves as a primer. Reverse transcription from tRNA(Lys-3) is not confined to cDNA synthesis of the 5' end of the viral RNA but extends across various regions of the viral genome through in vitro strand transfer events. Co-extraction of tRNA(Lys-3) has been overlooked thus far, despite its potential to introduce bias in downstream, reverse transcription-related applications. The observed events in the tRNA(Lys-3)-induced in vitro reverse transcription resemble in vivo replication processes. Therefore, these reactions may offer a unique model to better understand the replication dynamics of HIV-1., Competing Interests: The authors declare no conflict of interest.
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- 2024
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12. Treatment patterns in older patients with locally advanced head and neck squamous cell carcinoma: Results from an EORTC led survey.
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Oosting SF, Desideri I, Staelens D, Caballero C, Tribius S, Simon C, Singer S, Grégoire V, Fortpied C, and Luciani A
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- Aged, Humans, Quality of Life, Squamous Cell Carcinoma of Head and Neck therapy, Surveys and Questionnaires, Carcinoma, Squamous Cell therapy, Head and Neck Neoplasms therapy
- Abstract
Objectives: We aimed to assess patterns of care delivered to older patients with locally advanced head and neck squamous cell carcinoma (LA-HNSCC), and to analyze the use of geriatric assessment (GA) and assessment of quality of life (QoL)., Materials and Methods: Members of the head and neck cancer group and the older task force of the European Organisation for Research and Treatment of Cancer (EORTC), members the European Head and Neck Society and members of national groups in Europe were asked to complete a questionnaire about treatment delivered, use of GA, and QoL assessment in older patients with LA-HNSCC., Results: Investigators from 111 centers replied, including 90 (81.1%) academic centers, 16 (14.4%) community hospitals, and 5 (4.5%) private clinics. Large differences in treatment patterns were found. For instance, for oropharyngeal carcinoma, one third of the centers indicated that they treat <5% of older patients with chemoradiation, while 18 centers (16.2%) treat >40% of older patients with chemoradiation. Fourteen centers (12.6%) routinely perform GA, while 43 centers (38.7%) never do, and 39 centers (35.1%) sometimes do. QoL is assessed on a routine basis in one fifth of the centers., Conclusions: Large differences exist across institutions in the patterns of care delivered to older patients with LA-HNSCC. Prospective studies are required to learn how GA can guide treatment decisions, and how QoL and treatment outcome can be improved. For that, consensus on standard of care is essential., Competing Interests: Declaration of Competing Interest Dr. Oosting reports grants from Celldex, grants from Novartis, outside the submitted work; Dr. Singer reports personal fees from Pfizer, personal fees from Bristol-Myers Squibb, personal fees from Boehringer-Ingelheim, personal fees from Lilly, outside the submitted work; all other authors have nothing to disclose., (Copyright © 2021 Elsevier Ltd. All rights reserved.)
- Published
- 2021
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13. High frequency of new recombinant forms in HIV-1 transmission networks demonstrated by full genome sequencing.
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Hebberecht L, Mortier V, Dauwe K, Schauvliege M, Staelens D, Demecheleer E, Stoffels K, Vanroye F, Delforge ML, Vancutsem E, Dessilly G, Vaira D, Van Laethem K, and Verhofstede C
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- Belgium epidemiology, Drug Resistance, Viral genetics, Female, Genome, Viral, HIV Infections epidemiology, Homosexuality, Male, Humans, Male, Molecular Epidemiology, Phylogeny, Recombination, Genetic, Whole Genome Sequencing, HIV Infections transmission, HIV Infections virology, HIV-1 genetics
- Abstract
The HIV-1 epidemic in Belgium is primarily driven by MSM. In this patient population subtype B predominates but an increasing presence of non-B subtypes has been reported. We aimed to define to what extent the increasing subtype heterogeneity in a high at risk population induces the formation and spread of new recombinant forms. The study focused on transmission networks that reflect the local transmission to an important extent. One hundred and five HIV-1 transmission clusters were identified after phylogenetic analysis of 2849 HIV-1 pol sequences generated for the purpose of baseline drug resistance testing between 2013 and 2017. Of these 105 clusters, 62 extended in size during the last two years and were therefore considered as representing ongoing transmission. These 62 clusters included 774 patients in total. From each cluster between 1 and 3 representative patients were selected for near full-length viral genome sequencing. In total, the full genome sequence of 101 patients was generated. Indications for the presence of a new recombinant form were found for 10 clusters. These 10 clusters represented 105 patients or 13.6% of the patients covered by the study. The findings clearly show that new recombinant strains highly contribute to local transmission, even in an epidemic that is largely MSM and subtype B driven. This is an evolution that needs to be monitored as reshuffling of genome fragments through recombination may influence the transmissibility of the virus and the pathology of the infection. In addition, important changes in the sequence of the viral genome may challenge the performance of tests used for diagnosis, patient monitoring and drug resistance analysis., Competing Interests: Declaration of Competing Interest None., (Copyright © 2020 Elsevier B.V. All rights reserved.)
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- 2020
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14. Single genome sequencing of near full-length HIV-1 RNA using a limiting dilution approach.
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Hebberecht L, Vancoillie L, Schauvliege M, Staelens D, Demecheleer E, Hardy J, Mortier V, and Verhofstede C
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- DNA, Complementary genetics, Genotype, HIV Infections virology, Humans, Plasma virology, Polymerase Chain Reaction, Sensitivity and Specificity, HIV-1 genetics, RNA, Viral genetics, Whole Genome Sequencing methods
- Abstract
Sequencing very long stretches of the HIV-1 genome can advance studies on virus evolution and in vivo recombination but remains technically challenging. We developed an efficient procedure to sequence near full-length HIV-1 RNA using a two-amplicon approach. The whole genome was successfully amplified for 107 (88%) of 121 plasma samples including samples from patients infected with HIV-1 subtype A1, B, C, D, F1, G, H, CRF01_AE and CRF02_AG. For the 17 samples with a viral load below 1000 c/ml and the 104 samples with a viral load above 1000 c/ml, the amplification efficiency was respectively 53% and 94%. The sensitivity of the method was further evaluated using limiting dilution of RNA extracted from a plasma pool containing an equimolar mixture of three HIV-1 subtypes (B, C and CRF02_AG) and diluted before and after cDNA generation. Both RNA and cDNA dilution showed comparable sensitivity and equal accuracy in reflecting the subtype distribution of the plasma pool. One single event of in vitro recombination was detected amongst the 41 sequences obtained after cDNA dilution but no indications for in vitro recombination were found after RNA dilution. In conclusion, a two-amplicon strategy and limiting dilution of viral RNA followed by reverse transcription, nested PCR and Sanger sequencing, allows near full genome sequencing of individual HIV-1 RNA molecules. This method will be a valuable tool in the study of virus evolution and recombination., (Copyright © 2019 The Authors. Published by Elsevier B.V. All rights reserved.)
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- 2019
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15. A multinational, multi-tumour basket study in very rare cancer types: The European Organization for Research and Treatment of Cancer phase II 90101 'CREATE' trial.
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Péron J, Marreaud S, Staelens D, Raveloarivahy T, Nzokirantevye A, Flament J, Steuve J, Lia M, Collette L, and Schöffski P
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- Humans, Follow-Up Studies, International Agencies, Prognosis, Survival Rate, Multicenter Studies as Topic, Clinical Trials, Phase II as Topic, Antineoplastic Combined Chemotherapy Protocols therapeutic use, Neoplasms classification, Neoplasms drug therapy, Neoplasms pathology, Rare Diseases classification, Rare Diseases drug therapy, Rare Diseases pathology
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- 2019
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16. Quantification of total HIV-1 DNA in buffy coat cells, feasibility and potential added value for clinical follow-up of HIV-1 infected patients on ART.
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Mortier V, Demecheleer E, Staelens D, Schauvliege M, Dauwe K, Dinakis S, Hebberecht L, Vancoillie L, and Verhofstede C
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- Adult, Anti-HIV Agents therapeutic use, Antiretroviral Therapy, Highly Active, CD4 Lymphocyte Count, Cross-Sectional Studies, DNA Primers genetics, Follow-Up Studies, Genetic Markers, HIV Infections epidemiology, HIV Seropositivity, HIV-1 genetics, Humans, Longitudinal Studies, Male, Middle Aged, RNA, Viral, Real-Time Polymerase Chain Reaction, Reproducibility of Results, Retrospective Studies, Blood Buffy Coat virology, DNA, Viral analysis, HIV Infections drug therapy, Viral Load methods
- Abstract
Background: Successfully treated HIV-1 infected patients have a sustained undetectable viral RNA load. In these cases the total HIV-1 DNA load may constitute a valuable tool to further follow the overall viral burden. The value of this marker outside of cure research has been rarely studied., Objectives: To develop a quantitative (q)PCR for total HIV-1 DNA quantification in buffy coat cells and to evaluate the value of this parameter in clinical follow-up., Study Design: A qPCR using primers and a probe in the conserved HIV-1 LTR region was adapted for use on DNA extracted from buffy coat cells. Sensitivity, accuracy and reproducibility were evaluated using 8E5 cells and samples from naive and treatment experienced patients. The clinical value of DNA load analysis was assessed by testing 119 longitudinal samples from 9 patients before and after ART initiation and 249 cross sectional samples from therapy-experienced patients., Results: Inter- and intra-assay coefficients of variability were 5.56 and 5.94 (%CV). HIV-1 DNA was detected in 249 of the 263 (94.7%) patients on ART for at least 5 months (median: 53 months; IQR: 28-84 months). The HIV-1 DNA load varied between 0.60 and 3.37 copies/10
6 blood cells and showed significant correlation with the pre-ART CD4+ T-cell count nadir and peak viral RNA load. ART initiation resulted in a slow and limited decline of the total HIV-1 DNA concentration., Conclusions: Quantification of total HIV-1 DNA from buffy coat cells is feasible, sensitive and reliable. Although determination of the on-therapy HIV-1 DNA load may be informative, regular testing has limited clinical value because of the very slow evolution., (Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.)- Published
- 2018
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17. Frequency of occurrence of HIV-1 dual infection in a Belgian MSM population.
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Hebberecht L, Vancoillie L, Schauvliege M, Staelens D, Dauwe K, Mortier V, and Verhofstede C
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- Adult, Belgium epidemiology, HIV Envelope Protein gp120 genetics, HIV Infections virology, High-Throughput Nucleotide Sequencing, Homosexuality, Male, Humans, Male, Middle Aged, Peptide Fragments genetics, Phylogeny, Prevalence, Pyrroles, Retrospective Studies, Superinfection epidemiology, Superinfection virology, HIV Infections epidemiology, HIV-1 classification, HIV-1 genetics
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Introduction: HIV-1 dual infection is a condition that results from infection with at least two HIV-1 variants from different sources. The scarceness of information on this condition is partly due to the fact that its detection is technically challenging. Using next-generation sequencing we defined the extent of HIV-1 dual infection in a cohort of men who have sex with men (MSM)., Material & Methods: Eighty-six MSM, diagnosed with HIV-1 subtype B infection between 2008 and 2013 were selected for next-generation sequencing of the HIV-1 envelope V3. Sequencing was performed on 2 plasma samples collected with an interval of > 6 months before the initiation of antiretroviral therapy. Maximum likelihood phylogenetic trees were inspected for dual infection, defined as the presence of two or more monophyletic clusters with ≥ 90% bootstrap support and a mean between-cluster genetic distance of ≥ 10%. To confirm dual infection, deep V3 sequencing of intermediate samples was performed as well as clonal sequencing of the HIV-1 protease-reverse transcriptase gene., Results: Five of the 74 patients (6.8%) for whom deep sequencing was successful, showed clear evidence of dual infection. In 4 of them, the second strain was absent in the first sample but occurred in subsequent samples. This was highly suggestive for superinfection. In 3 patients both virus variants were of subtype B, in 2 patients at least one of the variants was a subtype B/non-B recombinant virus., Conclusions: Dual infection was confirmed in 6.8% of MSM diagnosed with HIV-1 in Belgium. This prevalence is probably an underestimation, because stringent criteria were used to classify viral variants as originating from a new infection event.
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- 2018
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18. Meticulous plasma isolation is essential to avoid false low-level viraemia in Roche Cobas HIV-1 viral load assays.
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Mortier V, Vancoillie L, Dauwe K, Staelens D, Demecheleer E, Schauvliege M, Dinakis S, Van Maerken T, Dessilly G, Ruelle J, and Verhofstede C
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- Biological Assay methods, Biological Assay standards, DNA Contamination, Humans, RNA, Viral, Reagent Kits, Diagnostic, Real-Time Polymerase Chain Reaction methods, Real-Time Polymerase Chain Reaction standards, Sensitivity and Specificity, HIV Infections diagnosis, HIV Infections virology, HIV-1 genetics, Viral Load, Viremia virology
- Abstract
Background: Pre-analytical sample processing is often overlooked as a potential cause of inaccurate assay results. Here we demonstrate how plasma, extracted from standard EDTA-containing blood collection tubes, may contain traces of blood cells consequently resulting in a false low-level HIV-1 viral load when using Roche Cobas HIV-1 assays., Methods: The presence of human DNA in Roche Cobas 4800 RNA extracts and in RNA extracts from the Abbott HIV-1 RealTime assay was assessed by quantifying the human albumin gene by means of quantitative PCR. RNA was extracted from plasma samples before and after an additional centrifugation and tested for viral load and DNA contamination. The relation between total DNA content and viral load was defined., Results: Elevated concentrations of genomic DNA were detected in 28 out of 100 Cobas 4800 extracts and were significantly more frequent in samples processed outside of the AIDS Reference Laboratory. An association between genomic DNA presence and spurious low-level viraemia results was demonstrated. Supplementary centrifugation of plasma before RNA extraction eliminated the contamination and the false viraemia., Conclusions: Plasma isolated from standard EDTA-containing blood collection tubes may contain traces of HIV DNA leading to false viral load results above the clinical cutoff. Supplementary centrifugation of plasma before viral load analysis may eliminate the occurrence of this spurious low-level viraemia.
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- 2018
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19. Deep Sequencing of HIV-1 RNA and DNA in Newly Diagnosed Patients with Baseline Drug Resistance Showed No Indications for Hidden Resistance and Is Biased by Strong Interference of Hypermutation.
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Dauwe K, Staelens D, Vancoillie L, Mortier V, and Verhofstede C
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- Female, HIV Protease genetics, HIV Reverse Transcriptase genetics, Humans, Male, Retrospective Studies, DNA, Viral genetics, Drug Resistance, Viral, HIV Infections virology, High-Throughput Nucleotide Sequencing, Mutation, RNA, Viral genetics
- Abstract
Deep sequencing of plasma RNA or proviral DNA may be an interesting alternative to population sequencing for the detection of baseline transmitted HIV-1 drug resistance. Using a Roche 454 GS Junior HIV-1 prototype kit, we performed deep sequencing of the HIV-1 protease and reverse transcriptase genes on paired plasma and buffy coat samples from newly diagnosed HIV-1-positive individuals. Selection was based on the outcome of population sequencing and included 12 patients with either a revertant amino acid at codon 215 of the reverse transcriptase or a singleton resistance mutation, 4 patients with multiple resistance mutations, and 4 patients with wild-type virus. Deep sequencing of RNA and DNA detected 6 and 43 mutations, respectively, that were not identified by population sequencing. A subsequently performed hypermutation analysis, however, revealed hypermutation in 61.19% of 3,188 DNA reads with a resistance mutation. The removal of hypermutated reads dropped the number of additional mutations in DNA from 43 to 17. No hypermutation evidence was found in the RNA reads. Five of the 6 additional RNA mutations and all additional DNA mutations, after full exclusion of hypermutation bias, were observed in the 3 individuals with multiple resistance mutations detected by population sequencing. Despite focused selection of patients with T215 revertants or singleton mutations, deep sequencing failed to identify the resistant T215Y/F or M184V or any other resistance mutation, indicating that in most of these cases there is no hidden resistance and that the virus detected at diagnosis by population sequencing is the original infecting variant., (Copyright © 2016, American Society for Microbiology. All Rights Reserved.)
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- 2016
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20. Visualization of delayed release of compounds from pH-sensitive capsules in vitro and in vivo in a hamster model.
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Staelens D, Liang S, Appeltans B, Van de Wouwer M, Van den Mooter G, Van Assche G, Himmelreich U, and Vande Velde G
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- Animals, Capsules administration & dosage, Capsules chemistry, Contrast Media chemistry, Cricetinae, Delayed-Action Preparations, Hydrogen-Ion Concentration, Polymethacrylic Acids administration & dosage, Polymethacrylic Acids chemistry, Tomography, X-Ray Computed, Contrast Media administration & dosage, Intestine, Small diagnostic imaging, Magnetic Resonance Imaging, Stomach diagnostic imaging
- Abstract
Delayed controlled release is an innovative strategy to locally administer therapeutic compounds (e.g. chemotherapeutics, antibodies etc.). This would improve efficiency and reduce side effects compared with systemic administration. To enable the evaluation of the efficacy of controlled release strategies both in vitro and in vivo, we investigated the release of contrast agents ((19)F-FDG and BaSO4) to the intestinal tract from capsules coated with pH-sensitive polymers (EUDRAGIT L-100) by using two complementary techniques, i.e. (19)F magnetic resonance imaging (MRI) and computed tomography (CT). Using in vitro (19)F-MRI, we were able to non-destructively and dynamically establish a time window of 2 h during which the capsules are resistant to low pH. With (19)F-MRI, we could establish the exact time point when the capsules became water permeable, before physical degradation of the capsule. This was complemented by CT imaging, which provided longitudinal information on physical degradation of the capsule at low pH that was only seen after 230 min. After oral administration to hamsters, (19)F-MRI visualized the early event whereby the capsule becomes water permeable after 2 h. Additionally, using CT, the integrity and location (stomach and small intestines) of the capsule after administration could be monitored. In conclusion, we propose combined (19)F-MRI and CT to non-invasively visualize the different temporal and spatial events regarding the release of compounds, both in an in vitro setting and in the gastrointestinal tract of small animal models. This multimodal imaging approach will enable the in vitro and in vivo evaluation of further technical improvements to controlled release strategies., (Copyright © 2015 John Wiley & Sons, Ltd.)
- Published
- 2016
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21. Strong Upregulation of AIM2 and IFI16 Inflammasomes in the Mucosa of Patients with Active Inflammatory Bowel Disease.
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Vanhove W, Peeters PM, Staelens D, Schraenen A, Van der Goten J, Cleynen I, De Schepper S, Van Lommel L, Reynaert NL, Schuit F, Van Assche G, Ferrante M, De Hertogh G, Wouters EF, Rutgeerts P, Vermeire S, Nys K, and Arijs I
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- Adult, Aged, Biopsy, Case-Control Studies, Caspase 1 metabolism, Cohort Studies, DNA-Binding Proteins genetics, Epithelial Cells metabolism, Female, HMGB1 Protein metabolism, Humans, Immunity, Innate, Male, Middle Aged, Nuclear Proteins genetics, Phosphoproteins genetics, Transcriptional Activation, Up-Regulation, DNA-Binding Proteins metabolism, Inflammasomes genetics, Inflammatory Bowel Diseases pathology, Intestinal Mucosa pathology, Nuclear Proteins metabolism, Phosphoproteins metabolism, Signal Transduction
- Abstract
Background: Inflammatory bowel disease (IBD) is characterized by a chronic inflammation of the gut, partly driven by defects in the innate immune system. Considering the central role of inflammasome signaling in innate immunity, we studied inflammasome components in IBD mucosa., Methods: Expression of genes encoding inflammasome sensor subunits was investigated in colonic mucosal biopsies from 2 cohorts of patients with IBD and controls., Results: A significant upregulation (>2-fold change in expression, false discovery rate <0.05) of the PYHIN inflammasomes AIM2 and IFI16 in active IBD versus controls was found. Also IFI16 was significantly increased in inactive IBD versus controls. Moreover, responders to anti-tumor necrosis factor therapy showed decreased expression of these inflammasomes although IFI16 remained significantly increased in responders showing endoscopic healing versus controls. AIM2 was mainly expressed in epithelial cells, whereas IFI16 was expressed in both lymphocytes and epithelial cells. Functional activation of predominant AIM2/IFI16-mediated inflammasomes in active IBD colon was shown by the presence of the downstream effectors CASP1 and HMGB-1 in inflamed mucosa., Conclusions: Our results highlight the importance of PYHIN inflammasome signaling in IBD and also link anti-tumor necrosis factor responsiveness to inflammasome signaling. Together, this points to the potential value of the inflammasome pathway as a new therapeutic target for IBD treatment.
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- 2015
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22. Genetic and microbial factors modulating the ubiquitin proteasome system in inflammatory bowel disease.
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Cleynen I, Vazeille E, Artieda M, Verspaget HW, Szczypiorska M, Bringer MA, Lakatos PL, Seibold F, Parnell K, Weersma RK, Mahachie John JM, Morgan-Walsh R, Staelens D, Arijs I, De Hertogh G, Müller S, Tordai A, Hommes DW, Ahmad T, Wijmenga C, Pender S, Rutgeerts P, Van Steen K, Lottaz D, Vermeire S, and Darfeuille-Michaud A
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- Bacterial Adhesion, Case-Control Studies, Cell Survival, Cells, Cultured, Colitis, Ulcerative enzymology, Colitis, Ulcerative microbiology, Crohn Disease enzymology, Crohn Disease microbiology, Deubiquitinating Enzyme CYLD, Dystroglycans genetics, Epithelial Cells microbiology, Escherichia coli pathogenicity, Genetic Association Studies, Humans, I-kappa B Proteins metabolism, Intestinal Mucosa microbiology, NF-kappa B metabolism, Peptide Hydrolases genetics, Polymorphism, Single Nucleotide, Proteasome Endopeptidase Complex metabolism, Tumor Suppressor Proteins genetics, Ubiquitin Thiolesterase genetics, Ubiquitin-Specific Proteases genetics, Colitis, Ulcerative genetics, Crohn Disease genetics, Epithelial Cells enzymology, Tumor Suppressor Proteins metabolism
- Abstract
Objective: Altered microbiota composition, changes in immune responses and impaired intestinal barrier functions are observed in IBD. Most of these features are controlled by proteases and their inhibitors to maintain gut homeostasis. Unrestrained or excessive proteolysis can lead to pathological gastrointestinal conditions. The aim was to validate the identified protease IBD candidates from a previously performed systematic review through a genetic association study and functional follow-up., Design: We performed a genetic association study in a large multicentre cohort of patients with Crohn's disease (CD) and UC from five European IBD referral centres in a total of 2320 CD patients, 2112 UC patients and 1796 healthy controls. Subsequently, we did an extensive functional assessment of the candidate genes to explore their causality in IBD pathogenesis., Results: Ten single nucleotide polymorphisms (SNPs) in four genes were significantly associated with CD: CYLD, USP40, APEH and USP3. CYLD was the most significant gene with the intronically located rs12324931 the strongest associated SNP (p(FDR)=1.74e-17, OR=2.24 (1.83 to 2.74)). Five SNPs in four genes were significantly associated with UC: USP40, APEH, DAG1 and USP3. CYLD, as well as some of the other associated genes, is part of the ubiquitin proteasome system (UPS). We therefore determined if the IBD-associated adherent-invasive Escherichia coli (AIEC) can modulate the UPS functioning. Infection of intestinal epithelial cells with the AIEC LF82 reference strain modulated the UPS turnover by reducing poly-ubiquitin conjugate accumulation, increasing 26S proteasome activities and decreasing protein levels of the NF-κB regulator CYLD. This resulted in IκB-α degradation and NF-κB activation. This activity was very important for the pathogenicity of AIEC since decreased CYLD resulted in increased ability of AIEC LF82 to replicate intracellularly., Conclusions: Our results reveal the UPS, and CYLD specifically, as an important contributor to IBD pathogenesis, which is favoured by both genetic and microbial factors., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)
- Published
- 2014
- Full Text
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23. Infliximab restores the dysfunctional matrix remodeling protein and growth factor gene expression in patients with inflammatory bowel disease.
- Author
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de Bruyn M, Machiels K, Vandooren J, Lemmens B, Van Lommel L, Breynaert C, Van der Goten J, Staelens D, Billiet T, De Hertogh G, Ferrante M, Van Assche G, Vermeire S, Opdenakker G, Schuit F, Rutgeerts P, and Arijs I
- Subjects
- Adult, Aged, Anti-Inflammatory Agents, Non-Steroidal administration & dosage, Biopsy, Dose-Response Relationship, Drug, Female, Humans, Immunohistochemistry, Inflammatory Bowel Diseases genetics, Inflammatory Bowel Diseases metabolism, Infliximab, Intercellular Signaling Peptides and Proteins biosynthesis, Intestinal Mucosa drug effects, Intestinal Mucosa metabolism, Intestinal Mucosa pathology, Male, Matrix Metalloproteinases biosynthesis, Middle Aged, Prospective Studies, Real-Time Polymerase Chain Reaction, Treatment Outcome, Tumor Necrosis Factor-alpha antagonists & inhibitors, Young Adult, Antibodies, Monoclonal administration & dosage, Gene Expression Regulation drug effects, Inflammatory Bowel Diseases drug therapy, Intercellular Signaling Peptides and Proteins genetics, Matrix Metalloproteinases genetics, RNA genetics
- Abstract
Background: Matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs), a disintegrin and metalloprotease with thrombospondin motifs [ADAM(TS)s] and growth factors are involved in inflammation and tissue damage and repair, all occurring in inflammatory bowel disease (IBD). We studied the impact of anti-inflammatory therapy with infliximab on mucosal expression of these tissue remodeling genes in patients with IBD., Methods: Mucosal gene expression of 23 MMPs, 4 TIMPs, 50 ADAM(TS)s, and 158 growth factors was investigated in 61 patients with IBD before and after the first infliximab therapy and in 12 controls, with microarrays and quantitative RT-PCR. Protein localization, mucosal gelatinase levels, and net gelatinolytic activity were investigated by immunohistochemistry, zymography analysis, and gelatin degradation assay, respectively., Results: In patients with active IBD before infliximab versus controls, gene expression of many MMPs, TIMPs, ADAM(TS)s, and growth factors was upregulated, whereas colonic expression of MMP28 and TGFA and ileal expression of ADAMDEC1 and AGT were downregulated. After controlling inflammation with infliximab, most gene dysregulations observed at baseline were restored in responders. Increased ratio of MMP1/TIMP1 expression at baseline in active IBD was restored in responders with colonic mucosal healing. With immunohistochemistry, protein localization differences of MMP1, MMP3, REG1A, and TIMP1 were shown between active IBD and control mucosa. With zymography analysis and gelatin degradation assay, higher gelatinase levels and net gelatinolytic activity were measured before infliximab and levels normalized after infliximab., Conclusions: Our data suggest that suppression of inflammation results in the arrest of epithelial damage and subsequent mucosal healing. Therefore, the therapeutic potential of agents targeting MMPs or growth factors as primary therapy seems rather complex.
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- 2014
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24. Frequency and predictors of HIV-1 co-receptor switch in treatment naive patients.
- Author
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Mortier V, Dauwe K, Vancoillie L, Staelens D, Van Wanzeele F, Vogelaers D, Vandekerckhove L, Chalmet K, and Verhofstede C
- Subjects
- Anti-Retroviral Agents pharmacology, CCR5 Receptor Antagonists pharmacology, Cyclohexanes pharmacology, Genotype, HIV-1 drug effects, HIV-1 genetics, Humans, Maraviroc, Phylogeny, Triazoles pharmacology, Receptors, CCR5 metabolism, Receptors, CXCR4 metabolism
- Abstract
Background: Determination of HIV-1 co-receptor use is a necessity before initiation of a CCR5 antagonist but the longevity of a CCR5-use prediction remains unknown., Methods: Genotypic co-receptor tropism determination was performed in 225 newly diagnosed individuals consulting an AIDS Reference Centre. Samples were collected at diagnosis and at initiation of antiretroviral therapy or just before closure of the study for patients who did not initiate therapy. For individuals with a discordant tropism prediction on the two longitudinal samples, analysis of intermediate samples and single genome sequencing of proviral DNA was performed to confirm the tropism switch. Deep sequencing was done to identify minor CXCR4 or CCR5-using populations in the initial sample., Results: Overall, tropism switches were rare (7.6%). Only a geno2pheno false positive rate of <50% at baseline was retained as predictive for a subsequent switch from CCR5-use only to predicted CXCR4-use. Minor CXCR4-using virus populations were detected in the first sample of 9 of the 14 R5-to-X4 switchers but the subsequent outgrowth of these minor populations was documented in only 3., Conclusions: With the current guidelines for treatment initiation at CD4(+) T cell counts of <500 cells/mm(3), co-receptor switch between diagnosis and starting antiretroviral therapy is rare. Patients with R5 viruses and a geno2pheno FPR of <50% are more prone to subsequent co-receptor switch than patients with an FPR of >50% and will need repeat tropism testing if initiation of maraviroc is considered and previous testing dates from more than a year before.
- Published
- 2013
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25. Interleukin-15 receptor α expression in inflammatory bowel disease patients before and after normalization of inflammation with infliximab.
- Author
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Perrier C, Arijs I, Staelens D, Breynaert C, Cleynen I, Covens K, Ferrante M, Van Assche G, Vermeire S, de Hertogh G, Schuit F, Rutgeerts P, and Ceuppens JL
- Subjects
- Adult, Anti-Inflammatory Agents, Non-Steroidal therapeutic use, Colitis, Ulcerative immunology, Crohn Disease immunology, Enzyme-Linked Immunosorbent Assay, Female, Fluorescent Antibody Technique, Humans, Immunohistochemistry, Inflammation drug therapy, Infliximab, Interleukin-15 Receptor alpha Subunit genetics, Male, Middle Aged, RNA, Messenger genetics, Reverse Transcriptase Polymerase Chain Reaction, Young Adult, Anti-Inflammatory Agents, Non-Steroidal pharmacology, Antibodies, Monoclonal pharmacology, Antibodies, Monoclonal therapeutic use, Colitis, Ulcerative drug therapy, Crohn Disease drug therapy, Interleukin-15 Receptor alpha Subunit biosynthesis, Interleukin-15 Receptor alpha Subunit immunology
- Abstract
Interleukin-15 (IL-15) is a pro-inflammatory cytokine thought to contribute to the inflammation in inflammatory bowel diseases (IBD). The specific receptor chain IL-15Rα can be expressed as a transmembranous signalling receptor, or can be cleaved by a disintegrin and metalloprotease domain 17 (ADAM17) into a neutralizing, soluble receptor (sIL-15Rα). The aim of this study is to evaluate the expression of IL-15Rα in ulcerative colitis (UC) and Crohn's disease (CD) patients before and after infliximab (IFX) therapy. Gene expression of IL-15Rα, IL-15 and ADAM17 was measured at the mRNA level by quantitative reverse transcription-PCR in mucosal biopsies harvested before and after first IFX therapy. Concentrations of sIL-15Rα were measured in sera of patients by ELISA and IL-15Rα protein was localized in the gut by immunohistochemistry and immunofluorescence. Mucosal expression of IL-15Rα is increased in UC and CD patients compared with controls and it remains elevated after IFX therapy in both responder and non-responder patients. The concentration of sIL-15Rα in serum is also increased in UC patients when compared with controls and does not differ between responders and non-responders either before or after IFX. CD patients have levels of sIL-15Rα comparable to healthy controls before and after therapy. In mucosal tissues, IL-15Rα(+) cells closely resemble activated memory B cells with a pre-plasmablastic phenotype. To conclude, IBD patients have an increased expression of IL-15Rα mRNA in the mucosa. Expression is localized in B cells, suggesting that IL-15 regulates B-cell functions during bowel inflammation. No change in release of sIL-15Rα is observed in patients treated with IFX., (© 2012 Blackwell Publishing Ltd.)
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- 2013
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26. Conformational variability of the synthetic peptide 129-141 of the mouse prion protein.
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Prévost M, Jacquemotte F, Oberg KA, Staelens D, Devreese B, and Van Beeumen J
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- Animals, Circular Dichroism, Hydrogen-Ion Concentration, Lysophosphatidylcholines pharmacology, Mice, Micelles, Models, Molecular, Protein Conformation, Protein Structure, Secondary, Sodium Chloride pharmacology, Sodium Dodecyl Sulfate pharmacology, Peptides chemistry, Prions chemistry
- Abstract
The effect of solution conditions on the conformation of the peptide corresponding to residues 129-141 of the mouse prion protein has been examined by experimental and theoretical tools including circular dichroism, secondary structure predictions, and Molecular Dynamics simulations. The conformational properties of the peptide observed by CD confirm the prediction results: the peptide is chiefly random coil in water. The conformational sampling performed by Molecular Dynamics simulations in water also corroborates the flexibility of the peptide, in particular for the N-terminal part. We show, however, that the peptide samples hairpin conformations in one of several approximately 1-ns Molecular Dynamics simulations in water. Interestingly, the analysis of the CD spectra obtained in this study suggests the presence of beta-structure which, given the length of the peptide, can only consist in beta-hairpin. The peptide can also be induced to form a modest percentage of helical structure in the presence of organic cosolvents such as trifluoroethanol, or detergents such as sodium dodecyl sulfate and lysophosphatidylcholine. This result is different from that obtained for a homologous hamster fragment, which differs from the mouse sequence by the single substitution of Ile 139 to Met. Interestingly, this substitution is crucial for the barrier in the transmission of the prion disease between hamsters and mice.
- Published
- 2000
- Full Text
- View/download PDF
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