References of "Heinen, Ernst"
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See detailNeutrophil Extracellular Traps (NET) Entrap and Kill Borrelia burgdorferi sensu stricto Spirochetes and Are not Affected by Ixodes ricinus Tick Saliva.
MENTEN-DEDOYART, Catherine ULg; Faccinetto, Céline; Golovchenko, Maryna et al

in Journal of Immunology (2012), 189(11), 5393-5401

Lyme disease is a pathology caused by members of the Borrelia burgdorferi sensu lato (s.l.) complex, most often by B. burgdorferi sensu stricto (s.s.). They are transmitted mainly by Ixodes ricinus ticks ... [more ▼]

Lyme disease is a pathology caused by members of the Borrelia burgdorferi sensu lato (s.l.) complex, most often by B. burgdorferi sensu stricto (s.s.). They are transmitted mainly by Ixodes ricinus ticks. After a few hours of infestation, neutrophils massively infiltrate the bite site. They can kill Borrelia via phagocytosis, oxidative burst and hydrolytic enzymes. However, factors in tick saliva promote propagation of the bacteria in the host even in the presence of a large number of neutrophils. Neutrophil extracellular trap (NET) consists in the extrusion of the neutrophil’s own DNA, forming traps that can retain and kill bacteria. The production of reactive oxygen species (ROS) is apparently associated with the onset of NEtosis. Here we describe NETs formation at the tick bite site in vivo in mice. We show that Borrelia burgdorferi s.s. spirochetes become trapped and killed by NETs in humans and that the bacteria do not seem to release significant nucleases to evade this process. Saliva from I. ricinus did not affect NET formation by human neutrophiles or it stability. However, it strongly decreased neutrophil ROS production, suggesting that a strong decrease of hydrogen peroxide does not affect NET formation. Finally, round bodies were observed trapped in NETs, some of them staining as live cells. This observation could help contribute to a better explanation of erythema migrans. [less ▲]

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See detailDecontamination of Prions by the Flowing Afterglow of a Reduced-Pressure N2-O2 Cold-Plasma
Elmoualij, Benaïssa ULg; Thellin, Olivier ULg; GOFFLOT, Stéphanie ULg et al

in Plasma Processes and Polymers (2012), 9(6), 612618

Transmissible spongiform encephalopathies, also called prion diseases, represent a family of neurodegenerative disorders that affect various animal species. Since the infectious forms of prions are ... [more ▼]

Transmissible spongiform encephalopathies, also called prion diseases, represent a family of neurodegenerative disorders that affect various animal species. Since the infectious forms of prions are transmissible and highly resistant to chemical and physical decontamination methods routinely used in healthcare, they represent a challenge for science, medicine, and public health/food systems. Suitable decontamination procedures have been proposed, but they are generally incompatible with the materials from which medical devices are made. In this study, we evaluate a cold gaseous-plasma treatment, based on the outflow from a N2[BOND]O2 microwave discharge, as an alternative decontamination tool against both the non-infectious (PrPC) and infectious (PrPSc) forms of prion proteins. The efficiency of the plasma treatment on these proteins is assessed using an in vitro assay as well as an in vivo bioassay. We showed by Enzyme-Linked Immuno-Sorbent Assay (ELISA) that the N2[BOND]O2 discharge afterglow reduces the immunoreactivity of both non-infectious recombinant and pathogenic prion proteins deposited on polystyrene substrates. Tests done in vivo demonstrate that exposure to the cold-plasma flowing afterglow achieves significant decontamination of stainless steel sutures inoculated with infectious forms of prions to be implanted in mice. [less ▲]

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See detailPoly(2-dimethylamino ethylmethacrylate)-Based Polymers To Camouflage Red Blood Cell Antigens
Cerda Cristerna, Bernardino Isaac ULg; COTTIN, Sophie ULg; Flebus, Luca ULg et al

in Biomacromolecules (2012), 13(4), 1172-1180

Poly(2-dimethylamino-ethylmethacrylate) (PDMAEMA) is a cationic polymer when dissolved in a 7.4 pH fluid. Owing to its ionic nature, this polycation interacts with the negatively charged cell membrane ... [more ▼]

Poly(2-dimethylamino-ethylmethacrylate) (PDMAEMA) is a cationic polymer when dissolved in a 7.4 pH fluid. Owing to its ionic nature, this polycation interacts with the negatively charged cell membrane surface of red blood cells (RBCs). The electrostatic self-assembly of PDMAEMA on RBCs membrane can be employed for inducing the formation of a polymeric shield camouflaging blood group antigens on RBCs as a valuable strategy for developing “universal RBCs” for blood transfusion. The purpose of this research was to evaluate the camouflaging ability of PDMAEMA homopolymers and PDMAEMA-copoly(nethylene glycol) copolymers differing in molecular weight and architecture. Surprisingly, the PDMAEMAs caused a partially masking, no masking, and sensitization of the same RBCs population. The MW and architecture of the polymers as well as temperature of PDMAEMA-RBCs treatment influenced the results observed. Herein, the very particular reactivity of PDMAEMAs and RBCs is analyzed and discussed. [less ▲]

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See detailPre-Mortem Diagnostic Screening for Transmissible Spongiform Encephalopathies by Proteomic Approaches
Falisse-Poirrier, Nandini; Thellin, Olivier ULg; Dupiereux-Fettweis, Ingrid ULg et al

Book published by Nova Publishers (2012)

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See detailDetection of Clostridium botulinum neurotoxins A and B in milk by ELISA and immuno-PCR at higher sensitivity than mouse bio-assay
Rajkovic, Andreja; Elmoualij, Benaïssa ULg; Fikri, Youssef et al

in Food Analytical Methods (2011), [Epub ahead of print]

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See detailAlzheimer’s diseases: towards biomarkers for an early diagnosis
Elmoualij, Benaïssa ULg; Dupiereux-Fettweis, Ingrid ULg; Seguin, jérémie et al

Book published by InTech (2011)

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See detailKinetic study of the antibody response during the blood meal of Ixodes ricinus: Implication on plasma cell maturation in vivo and for anti-Ixodes vaccination
MENTEN, Catherine ULg; couvreur, B.; Jolois, Olivier ULg et al

in Vaccine (2011)

Anti-tick vaccination could be an ideal solution to prevent pathogen transmission, but none is currently available against Ixodes ticks. Recently, we showed that adult Ixodes ricinus infestation on mice ... [more ▼]

Anti-tick vaccination could be an ideal solution to prevent pathogen transmission, but none is currently available against Ixodes ticks. Recently, we showed that adult Ixodes ricinus infestation on mice decreases the specific antibody production to BSA injected during infestation. Here, a kinetic study of seric levels of BSA-specific antibodies was performed to evaluate the B memory cell differentiation in Balb/c mice and the capacity of specific B memory cells to respond to BSA during infestation. We concluded that the tick blood meal inhibits or impairs the local differentiation of mature B cells into plasma cells, but does not alter the formation of memory B cell. Accordingly, this mechanism should not be an impediment to anti-Ixodes vaccination. [less ▲]

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See detailBiofilms bactériens et médecine dentaire
Simain-Sato, Franklin ULg; Rompen, Eric ULg; Heinen, Ernst ULg

in Revue Médicale de Liège (2010), 65 (10)

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See detailSpreading of prions from the immune to the peripheral nervous system: a potential implication of dendritic cells.
Dorban, Gauthier; Defaweux, Valérie ULg; Heinen, Ernst ULg et al

in Histochemistry & Cell Biology (2010), 133(5), 493-504

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See detailTravaux pratiques en Histologie Humaine, Quadrimestre 3
Defaweux, Valérie ULg; Mélot, France ULg; Florquin, Sandra ULg et al

Learning material (2010)

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See detailTravaux pratiques en Histologie Humaine, Quadrimestre 4, 5 et 6
Defaweux, Valérie ULg; Mélot, France ULg; Florquin, Sandra ULg et al

Learning material (2010)

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See detailGerminal centres
Thielen, Caroline ULg; Heinen, Ernst ULg

in Encyclopedia of Life Sciences (2010)

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See detailImmunological discrimination between self and non self
Defaweux, Valérie ULg; Heinen, Ernst ULg

in Encyclopedia of Life Sciences (2010)

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See detailPreliminary characterization of jejunocyte and colonocyte cell lines isolated by enzymatic digestion from adult and young cattle.
Loret, Suzanne; Rusu, Dorina; Moualij, Benaissa El et al

in Research in Veterinary Science (2009), 87(1), 123-32

In the present study we developed an enzymatic approach (through the use of collagenase and dispase) to isolate bovine intestinal epithelial cells. Using this method, freshly isolated jejunocytes could be ... [more ▼]

In the present study we developed an enzymatic approach (through the use of collagenase and dispase) to isolate bovine intestinal epithelial cells. Using this method, freshly isolated jejunocytes could be distinguished from simultaneously isolated colonocytes, as the jejunocytes specifically exhibited the small intestinal peptidase gene transcript, as well as an active alkaline phosphatase. The transformation of both types of cell suspension was performed by retroviral infection, using reproduction-defective viruses bearing the gene coding for the large T antigen of the leukaemia simian virus (SV40). The success of the transfection was demonstrated by (1) a significant increase in cell passage numbers (52-53 vs. 7 passages for non-transfected cells), (2) the detection of both the large T transcript and the large T antigen in transformed cells. Possible contamination and progressive substitution of bovine primocultures by non-bovine lineages available in the laboratory was excluded, as the transformed cells presented a bovine typical karyotype. Most transfected cells kept an epithelial morphology after transformation. They also maintained the expression of FABP and enterocyte specific enzymes (brush-border associated maltase and IAP). However, levels of specific activity of these enzymes were low, suggesting that cell differentiation is not completely achieved under the applied culture conditions. [less ▲]

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See detailA decade of improvements in quantification of gene expression and internal standard selection.
Thellin, Olivier ULg; Elmoualij, Benaïssa ULg; Heinen, Ernst ULg et al

in Biotechnology Advances (2009)

Major improvements have been made in mRNA quantification and internal standard selection over the last decade. Our aim in this paper is to present the main developments that are of interest for practical ... [more ▼]

Major improvements have been made in mRNA quantification and internal standard selection over the last decade. Our aim in this paper is to present the main developments that are of interest for practical laboratory work, contrasting the situation as it is now with the one of ten years ago, and presenting some excellent examples of what can be done today. Specifically, we will mainly discuss Real-Time RT-PCR major improvements that have been performed in the following areas: the most commonly used quantification techniques, the mathematical and software tools created to help researchers in their work on internal standard selection, the availability of detection chemistries and technical information and of commercial tools and services. In addition to mRNA quantification, we will also discuss some aspects of non-coding RNA and protein quantification. In addition to technical improvements, the development of international cooperation and the creation of technical databases are likely to represent a major tool for the future in the standardization of gene expression quantification. [less ▲]

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See detailCreutzfeldt-jakob, Parkinson, lewy body dementia and Alzheimer diseases: from diagnosis to therapy.
Dupiereux-Fettweis, Ingrid ULg; Zorzi, Willy ULg; Quadrio, Isabelle et al

in Central Nervous System Agents in Medicinal Chemistry (2009), 9(1), 2-11

Depositions of proteins in form of amyloid and non-amyloid plaques are common pathogenic signs of more than 20 degenerative diseases affecting the central nervous system or a variety of peripheral tissues ... [more ▼]

Depositions of proteins in form of amyloid and non-amyloid plaques are common pathogenic signs of more than 20 degenerative diseases affecting the central nervous system or a variety of peripheral tissues. Among the neuropathological conditions, Alzheimer's, Parkinson's and the prion diseases, such as Creutzfeldt-Jakob disease (CJD), present ambiguities as regarding their differential diagnosis. At present, their diagnosis must be confirmed by post-mortem examination of the brain. Currently the ante-mortem diagnosis is still based on the integration of multiple data (clinical, paraclinical and biological analyses) because no unique marker exists for such diseases. The detection of specific biomarkers would be useful to develop a differential diagnostic, distinguishing not only different neurodegenerative diseases but also the disease from the non-pathological effects of aging. Several neurodegenerative biomarkers are present at very low levels during the early stages of the disease development and their ultra-low detection is needed for early diagnosis, which should permit more effective therapeutic interventions, before the disease concerned can progress to a stage where considerable damage to the brain has already occurred. In the case of prion diseases, there are concerns regarding not only patient care, but the wider community too, with regard to the risk of transmission of prions, especially during blood transfusion, for which, four cases of variant CJD infection associated with transfusion of non-leukocyte-depleted blood components have been confirmed. Therefore the development of techniques with high sensitivity and specificity represent the major challenge in the field of the protein misfolding diseases. In this paper we review the current analytical and/or biochemical diagnostic technologies used mainly in prion, but also in Alzheimer and Parkinson diseases and emphasizing work on the protein detection as a surrogates and specific biomarker in the body fluid of patients (urine, CSF and blood). This review highlights the urgency of the development of early and sensitive diagnostics in terms of therapeutic challenge. [less ▲]

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See detailGerminal centre innervation of bovine and human tonsils related to prion diseases.
Defaweux, Valérie ULg; Dorban, Gauthier; Antoine, Nadine ULg et al

in Brain, Behavior & Immunity (2009), 23(1), 10

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See detailIn vitro modelisation of prions neuroinvasion mediated by dendritic cells
Dorban, G.; Defaweux, Valérie ULg; Heinen, Ernst ULg et al

Poster (2008, October)

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See detail. Do innervation of germinal centre and contacts between FDC and nerve fibers be keys to understand the susceptibility difference between bovines and humans to the BSE agent?
Defaweux, Valérie ULg; Dorban, G.; Antoine, Nadine ULg et al

Poster (2008, October)

Background: In regard to BSE and vCJD, the agent tropism for lymphoid tissues is completely different even if the infectious strain responsible and the way of inoculation are identical. During vCJD, the ... [more ▼]

Background: In regard to BSE and vCJD, the agent tropism for lymphoid tissues is completely different even if the infectious strain responsible and the way of inoculation are identical. During vCJD, the infectious agent crosses the digestive barrier and multiplies in lymphoid organs, before progressively reaching the brain. Indeed, in vCJD, it accumulates in the ileum, tonsils, spleen and appendix of infected individuals. In contrast, in cattle, the BSE agent has a low affinity for lymphoid tissues and mainly accumulates in the nervous system. During preclinical stages, infectivity, other than that in the peripheral nervous system or central nervous system, is confined in the distal ileum of orally infected cattle. So, it appears that, at least in the case of BSE and vCJD, host properties can influence the accumulation of the infectious agent in lymphoid organs. Objectives and methods: In this study, we analysed by confocale microscopy the mucosal innervation and the interface between nerve fibres and FDC in bovine and human tonsils using a panel of antibodies. Since differences in the innervation of lymphoid organs depending on species and on age have been reported, we analysed two categories of bovines (calves less than 12 months old and bovines older than 24 months) and two categories of humans (patients less than 5 years old and patients older than 25 years). Results: In both species, ways of innervation by-passing germinal centres could be postulated: nerve fibres are widely distributed in antigen/cell traffic area: the lamina propria, the interfollicular zone and the lymphoepithelial area. We pointed out that, only in tonsils of bovines older than 24 months, nerve fibres are observed to be in contact with FDC. In contrast, in human tonsils, no nerve fibres established contacts with FDC, whatever the age. Discussion: Innervation of germinal centres can be said to be an age-dependent dynamic process in bovines. The weak innervation of the secondary lymphoid organs could thus be a rate-limiting step to neuroinvasion in humans. This species difference could influence the way of neuroinvasion and thus, the susceptibility of bovines and humans to the BSE agent. [less ▲]

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