References of "Thellin, Olivier"
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See detailIn vitro approach to study the synergistic effects of tobramycin and clarithromycin against Pseudomonas aeruginosa biofilms using prokaryotic or eukaryotic culture media
Thellin, Olivier ULg; Zorzi, Willy ULg; Jolois, Olivier et al

in International Journal of Antimicrobial Agents Corresponding (in press)

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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 detailSterilization/disinfection of medical devices using plasma: the reduced-pressure flowing-afterglow of the N2-O2 discharge as the inactivating medium
Michel Moisan; Jean Barbeau; Karim Boudama et al

in European journal of Applied Physics (2012)

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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 detailLa décontamination des prions selon les méthodes plasmas
Elmoualij, Benaïssa ULg; Thellin, Olivier ULg; Zorzi, Willy ULg

in Bioadh 2009 (2009, November 03)

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See detailRisk assessment of laboratories involving the manipulation of unconventional agents causing TSE
Leunda-Casi, A.; Pauwels, K.; Herman, Philippe et al

Report (2009)

The present document aims at summarizing the biosafety recommendations and the containment level required for laboratories where animal and human tissues potentially contaminated by a TSE (Transmissible ... [more ▼]

The present document aims at summarizing the biosafety recommendations and the containment level required for laboratories where animal and human tissues potentially contaminated by a TSE (Transmissible Spongiform Encephalitis) causing agent are manipulated. A particular attention will be paid to decontamination procedures, as the prion protein1 is remarkably resistant to conventional inactivation methods and may stay infectious for long periods of time. We will discuss large surface decontamination procedures of facilities handling TSE causing agents. This is of specific concern for laboratories that have been manipulating TSE causing agents, sometimes for years, but wish today dedicate the facilities to another activity. [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 detailProtective effect of prion protein via the N-terminal region in mediating a protective effect on paraquat-induced oxidative injury in neuronal cells.
Dupiereux-Fettweis, Ingrid ULg; Falisse-Poirier, Nandini; Zorzi, Willy ULg et al

in Journal of Neuroscience Research (2008), 86(3), 653-9

Transmissible spongiform encephalopathies are a group of neurodegenerative disorders caused by a posttranslational, conformational change in the cellular isoform of the prion protein (PrP(C)) into an ... [more ▼]

Transmissible spongiform encephalopathies are a group of neurodegenerative disorders caused by a posttranslational, conformational change in the cellular isoform of the prion protein (PrP(C)) into an infectious, disease-associated form (PrP(Sc)). Increasing evidence supports a role for PrP(C) in the cellular response to oxidative stress. We investigated the effect of oxidative stress mediated by paraquat exposure on SH-SY5Y neuroblastoma cells. A loss of mitochondrial membrane potential and subsequent reduction in ATP production were demonstrated in untransfected SH-SY5Y cells, an effect that was ameliorated by the expression of PrP(C). Cells expressing either PrP-DeltaOct, which lacks the octapeptide repeats, or PrP-DA, in which the N-terminus is tethered to the membrane, showed increased sensitivity to paraquat compared with cells expressing wild-type PrP(C) as shown by reduced viability, loss of their membrane integrity, and reduced mitochondrial bioenergetic measurements. Exposure of prion-infected mouse SMB15S cells to paraquat resulted in a reduction in viability to levels similar to those seen in the untransfected SH-SY5Y cells. However, "curing" the cells with pentosan sulfate restored the viability to the level observed in the SH-SY5Y cells expressing PrP(C). These data would indicate that the molecular mechanism promoting cellular resistance to oxidative stress had been compromised in the infected SMB15S cells, which could be reinstated upon curing. Our study supports the hypothesis that PrP(C) expression protects cells against paraquat-induced oxidative injury, demonstrates the significance of the N-terminal region of the protein in mediating this protective effect, and also shows that the biochemical consequences of prion infection may be reversed with therapeutic intervention. [less ▲]

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See detailInfluence of the Ixodes ricinus tick blood-feeding on the antigen-specific antibody response in vivo.
Menten-Dedoyart, Catherine ULg; Couvreur, B.; Thellin, Olivier ULg et al

in Vaccine (2008), 26(52), 6956-64

The blood meal of hard ticks such as Ixodes ricinus lasts several days. This is made possible by tick salivary factors that inhibit inflammation, haemostasis and the host immune response. We assessed the ... [more ▼]

The blood meal of hard ticks such as Ixodes ricinus lasts several days. This is made possible by tick salivary factors that inhibit inflammation, haemostasis and the host immune response. We assessed the latter on a model of immune response in vivo. A significant reduction of specific IgM and IgG levels was observed in BALB/c mice infested 5 days before injection with bovine serum albumin (BSA) and QuilA but not in mice infested 5 days after the immunization. This effect was not observed in mock-infested mice and could not be attributed to the use of anesthetics. The antibody response was not merely delayed and the Th(1)/Th(2) balance appeared not altered. T-dependent zones and germinal centers in lymph nodes draining the tick bite site showed no apparent morphological alterations or shift in T cell subpopulations. However, the spleens of tick-infested mice had also an enlarged red pulp, indicating an increased extramedullary haematopoietic activity. [less ▲]

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See detailOral scrapie infection modifies the homeostasis of Peyer's patches' dendritic cells
Dorban, Gauthier ULg; Defaweux, Valérie ULg; Levavasseur, Etienne et al

in Histochemistry & Cell Biology (2007), 128(3), 243-251

In transmitted prion diseases the immune system supports the replication and the propagation of the pathogenic agent (PrPSc). DCs, which are mobile cells present in large numbers within lymph organs, are ... [more ▼]

In transmitted prion diseases the immune system supports the replication and the propagation of the pathogenic agent (PrPSc). DCs, which are mobile cells present in large numbers within lymph organs, are suspected to carry prions through the lymphoid system and to transfer them towards the peripheral nervous system. In this study, C57Bl/6 mice were orally inoculated with PrPSc (scrapie strain 139A) and sacrificed at the preclinical stages of the disease. Immunolabelled cryosections of Peyer's patches were analysed by confocal microscopy. Membrane prion protein expression was studied by flow cytometry. In Peyer's patches (PP), dissected at day one and day 105 after oral exposure to scrapie, we observed an increased population of DCs localised in the follicular-associated epithelium. On day 105, PrPSc was found in the follicles inside the PP of prion-infected mice. A subset of Peyer's patches DCs, which did not express cellular prion protein on their surface in non-infected mice conditions, was prion-positive in scrapie conditions. Within Peyer's patches oral scrapie exposure thus induced modifications of the homeostasis of DCs at the preclinical stages of the disease. These results give new arguments in favour of the implication of DCs in prion diseases. [less ▲]

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See detailLa tremblante du mouton influence-t-elle le système immunitaire lors d’une réponse vis-à-vis d’un antigène
Defaweux, Valérie ULg; Dorban, G.; Demonceau, C. et al

Conference (2005, November)

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See detailL'infection par les prions pathogènes modifie l'expression menbranaire de la PrPc par les cellules dendritiques
Dorban, G; Demonceau,C; Levavasseur, E et al

Poster (2005, October)

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See detailInterfaces between dendritic cells, other immune cells, and nerve fibres in mouse Peyer's patches: Potential sites for neuroinvasion in prion diseases
Defaweux, Valérie ULg; Dorban, Gauthier ULg; Demonceau, Christine ULg et al

in Microscopy Research and Technique (2005), 66(1), 1-9

In this study, we examined where immune cells and nerve fibres are located in mouse Peyer's patches, with a view to identifying potential sites for neuroinvasion by prions. Special attention was paid to ... [more ▼]

In this study, we examined where immune cells and nerve fibres are located in mouse Peyer's patches, with a view to identifying potential sites for neuroinvasion by prions. Special attention was paid to dendritic cells, viewed as candidate transporters of infectious prion. Double immunofluorescence labellings with anti-CD11c antibody and marker for other immune cells (B cells, T cells, follicular dendritic cells) were carried out and analysed by confocal microscopy on Peyer's patch cryosections. To reveal the extensive ganglionated networks of the myenteric and submucosal plexi and the sparse meshworks of nerve strands, we used antibodies directed against different neurofilament subunits or against glial fibrillary acidic protein. In the suprafollicular dome, dendritic cells connect, via their cytoplasmic extensions, enterocytes with M cells of the follicle-associated epithelium. They are also close to B and T cells. Nerve fibres are detected in the suprafollicular dome, notably in contact with dendritic cells. Similar connections between dendritic cells, T cells, and nerve fibres are seen in the interfollicular region. Germinal centres are not innervated; inside them dendritic cells establish contacts with follicular dendritic cells and with B cells. After immunolabelling of normal prion protein, dendritic cells of the suprafollicular dome are intensely positive labelled. (c) 2005 Wiley-Liss, Inc. [less ▲]

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See detailPregnancy and the immune system: between tolerance and rejection
Thellin, Olivier ULg; Heinen, Ernst ULg

in Toxicology (2003), 185(3), 179-184

Interactions between the conceptus and the mother are bi-directional: the feto-placental tissues need nutrition and a suitable environment in homeostatic condition whereas the mother influenced by the ... [more ▼]

Interactions between the conceptus and the mother are bi-directional: the feto-placental tissues need nutrition and a suitable environment in homeostatic condition whereas the mother influenced by the placental factors adapts her metabolism and immune system. Many different mechanisms acting locally or at distance ensure tolerance of the semi-allogeneic graft by the maternal natural and adaptive immune defences. In front of this tolerance, mechanisms exist ensuring rejection of the conceptus by the mother (spontaneous abortion) through rupture of one or more tolerance mechanisms, notably in stress situations endangering the mother. Thus outcome of a pregnancy is dependent on efficiently working tolerance mechanisms, and rupture of such mechanisms can lead to rejection. The balance of influence leading either to tolerance or rejection is under control of internal (maternal and fetal) and external (environmental) factors. Rejection, if triggered, mainly occurs through immune-induced inflammation, tissue degradation and coagulation. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved. [less ▲]

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See detailProlactin Suppresses Glucocorticoid-Induced Thymocyte Apoptosis in Vivo
Krishnan, Nithya; Thellin, Olivier ULg; Buckley, Donna J. et al

in Endocrinology (2003), 144(5), 2102-2110

The hypothesis that prolactin (PRL) functions as an immunomodulator was based on studies showing lymphocyte PRL receptors, and its effects on growth, differentiation, and apoptosis in lymphoid cells ... [more ▼]

The hypothesis that prolactin (PRL) functions as an immunomodulator was based on studies showing lymphocyte PRL receptors, and its effects on growth, differentiation, and apoptosis in lymphoid cells. However, studies of PRL (PRL-/-) and PRL receptor knockout mice indicated that PRL was not required for immune system development or function under basal conditions. Because PRL maintains survival in glucocorticoid (GC)-treated Nb2-T lymphocytes in vitro, and PRL and GCs are elevated during stress, we investigated whether PRL protected T cells in vivo from GC-induced apoptosis. Adrenalectomized mice [PRL -/-, undetectable PRL; pituitary grafted PRL-/- (PRL-/-Graft), elevated PRL; and PRL+/-, normal PRL] were treated with dexamethasone (DEX) or PBS. Thymocytes and splenocytes were isolated and annexin V labeling of phosphatidylserine, DNA fragmentation, and caspase-3 activation were assessed as indices of apoptosis. Total thymocytes and CD4+ and CD8+ T cells obtained from DEX-treated PRL-/- mice exhibited significantly increased annexin V binding. In contrast, binding was not altered by DEX in PRL-/-Graft thymocytes. In addition, DEX induced classic DNA fragmentation in PRL-/- thymocytes. Elevated serum PRL reduced this effect. Thymocytes from DEX-treated PRL-/- mice exhibited increased caspase-3 activation, which was inhibited in cells from PRL-/-Graft mice. Finally, elevated expression of X-linked inhibitor of apoptosis, XIAP, was observed in thymi from DEX-treated PRL -/-Graft mice. This is the first demonstration that elevated PRL antagonizes apoptosis in thymocytes exposed to GCs in vivo. These observations suggest that, under conditions of increased GCs, such as during stress, elevated PRL functions physiologically to maintain survival and function of T-lymphocytes. [less ▲]

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See detailEffects of prolactin deficiency on myelopoiesis and splenic T lymphocyte proliferation in thermally injured mice.
Dugan, Amy L.; Thellin, Olivier ULg; Buckley, Donna J. et al

in Endocrinology (2002), 143(10), 4147-4151

The importance of prolactin (PRL) in mammopoiesis and milk production is undisputed. However, previous studies investigating the role of PRL in immune function have yielded inconsistencies. These ... [more ▼]

The importance of prolactin (PRL) in mammopoiesis and milk production is undisputed. However, previous studies investigating the role of PRL in immune function have yielded inconsistencies. These inconsistencies have led to our hypothesis that the immunomodulatory effects of PRL are only manifest under conditions in which the organism is subjected to stress. Thermal injury is a well-known stressor. The goal of this study was to determine whether the lack of PRL enhanced the negative effects of thermal injury-induced immune alterations utilizing a mouse model in which the PRL gene had been disrupted. Mice received either sham or burn treatment, and were sacrificed 4 days later. The immune parameters studied were the capacity of bone marrow cells to form granulocyte-macrophage colony forming units (GM-CFU) in the presence of granulocyte-macrophage colony stimulating factor, and the ability of the splenic T lymphocytes to proliferate in response to phytohemagglutin (PHA). As shown by others, our results reveal that burn increased the number of GM-CFU compared to sham controls; however, this elevation was only significant in the PRL-/- mice. Thermal injury increased PHA-stimulated proliferation of splenic T lymphocytes, however this increase was only significant in the PRL+/- group. We conclude that under conditions of a controlled stress event (thermal injury) [a] the increase in the GM-CFU is exaggerated in the absence of PRL, and [b] the enhancement of PHA-induced proliferation of splenic lymphocytes required PRL. This study supports the hypothesis that the immunomodulatory effects of PRL are manifest when the organism is subjected to stress. [less ▲]

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See detailStress hormone secretion and gut signal transducer (STAT) proteins after burn injury in rats.
Thellin, Olivier ULg; Noel, Greg; Khurana, Sudha et al

in Shock (2001), 16(5), 393-397

A burn injury triggers traumatic reactions characteristic of a stress. Here we investigated the early responses of prolactin (PRL), corticosterone (CS), and signal transducer and activator of ... [more ▼]

A burn injury triggers traumatic reactions characteristic of a stress. Here we investigated the early responses of prolactin (PRL), corticosterone (CS), and signal transducer and activator of transcription 5 (Stat5) in male Sprague-Dawley rats after burn injury. PRL and CS levels were determined in blood serum. Stat5 and phospho-Stat5 levels were determined in jejunum total protein extracts. The results confirmed an expected increase of CS between 4 and 6 hours following the burn injury. Unexpectedly, PRL secretion was suppressed during the same time frame. These hormone levels returned to normal 6 to 8 hours after burn injury. Stat5 was increased in the jejunum after burn injury, and its phosphorylation was increased between 8 and 11 hours after burn injury. These changes in Stat5 were not temporally correlated with either the hormone changes that we observed, or with previously documented changes of the gut function following burns. [less ▲]

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See detailTolerance to the Foeto-Placental 'Graft': Ten Ways to Support a Child for Nine Months
Thellin, Olivier ULg; Coumans, Bernard ULg; Zorzi, Willy ULg et al

in Current Opinion in Immunology (2000), 12(6), 731-7

Tolerance to the foetal 'allograft' has been extensively studied in the past few years, providing interesting new insights. In addition to a potential role for HLA-G, which has been widely discussed ... [more ▼]

Tolerance to the foetal 'allograft' has been extensively studied in the past few years, providing interesting new insights. In addition to a potential role for HLA-G, which has been widely discussed, there are hypotheses suggesting roles for several other molecules or cells: leukemia inhibitory factor and its receptor; indoleamine 2. 3-dioxygenase; the Th1/Th2 balance; suppressor macrophages; hormones such as progesterone or the placental growth hormone; CD95 and its ligand; and, as recently proposed, annexin II. Tolerance of the foetal allograft is probably the consequence of a wide panel of mechanisms that may or may not be pregnancy-specific, that are of major or secondary importance and that may be interconnected. [less ▲]

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See detailThe serum concentration of prolactin is suppressed and corticosterone is elevated in male rats following sublethal burn injury
Thellin, Olivier ULg; Noel, Greg; Khurana, Sudha et al

Poster (2000)

To improve the current clinical protocols used after a burn injury, injections of anabolic hormones like growth hormone (GH) or prolactin (PRL), which are also known to be immunostimulators has been ... [more ▼]

To improve the current clinical protocols used after a burn injury, injections of anabolic hormones like growth hormone (GH) or prolactin (PRL), which are also known to be immunostimulators has been suggested (Knox et al., 1995). Glucocorticoids, GH and PRL are considered stress hormones because their secretion is strongly altered by exposure to environmental stressors. Consistent with this concept, previous studies have suggested that the circulating levels of each of these hormones is increased by 24 h after a burn injury. However, the patterns of their secretion during the first hours after the burn injury is less well known. Working on male Sprague-Dawley rats, we have investigated the levels of corticosterone (CS) and PRL in the first hours after burn injury. Male rats were divided in three groups: 1) no treatment and no handling before execution (this allowed us to monitor the normal circadian cycle of the hormones); 2) rats are anesthesised using pentobarbitol, shaved and prepared for the burn, but not burned (sham-treated animals); 3) rats anesthesised and burned at 8AM. The rats were thereafter sacrified at specific times (day 1: 9AM, 10AM, 12PM, 4PM, 7PM; day 2: 8AM, 9AM, 10AM, 4PM, 7PM). Plasma was collected and the serum levels of CS and PRL were measured by ELISA and RIA, respectively. The circadian cycle of CS showed the predicted nadir at 10AM, and peak at 4PM. CS levels were elevated 6-fold by 1h after burn injury, reaching a maximum at 600ng/ml at 10AM. The concentration was progressively reduced to normal levels by 6 h after the burn injury, and followed the normal pattern thereafter. In sham-treated animals, CS concentration was similar to the burned animals, but the maximum elevation was only 3-4-fold, and the return to normal concentration was faster, after only 4 hours. The normal circadian cycle of PRL peaked at 8AM (110ng/ml) at 8AM. In contrast to CS, serum PRL fell dramatically following burn injury to less than 20ng/ml, and stayed low for 4h folowing the burn injury. In sham-treated animals, the changes in PRL were similar, but less dramatic than in the burned animals. In conclusion anesthesia and burn stress have similar effects on hormone secretion, but burn represents a stronger stressor. In the immediate hours following burn injury the animal physiology is dominated by high levels of secretion of an immunosuppressor (CS) and low levels of a potential immunostimulator (PRL). [less ▲]

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