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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
321

Propriétés de surface des nanoparticules et interactions avec les cellules endothéliales vasculaires

Fakhari Tehrani, Soudeh 06 1900 (has links)
Les traitements et l’imagerie des tumeurs cérébrales malignes se sont avérés jusqu’à présent très peu efficaces, en raison de la présence de la barrière hémato-encéphalique (BHE) qui freine le passage des molécules thérapeutiques mais aussi diagnostiques vers les tissus du système nerveux central (SNC). Le développement de vecteurs nanométriques chargés en agents thérapeutiques et capables de traverser la BHE pourrait être une alternative pour améliorer la bio-distribution de principes actifs et d’agent d’imagerie au cerveau. Parmi les différents types de vecteurs proposés, les nanoparticules polymériques (NP) constituées de polymères dibloc comportant un bloc de poly (éthylène glycol) (PEG) pourrait présenter une solution prometteuse pour transporter des actifs à travers la BHE. La PEGylation de la surface des NPs améliore la stabilité colloïdale des NPs. De plus, elle diminue l'adsorption non spécifique des protéines à la surface de NPs (appelée aussi opsonisation). La vitesse de clairance des NPs est ainsi ralentie et les NPs circulent plus longtemps dans le sang. Malgré l’effet bénéfique de la couche de PEG à la surface des NPs, le rôle exact des propriétés de surface liées à la longueur de la chaîne PEG sur l'interaction des NPs avec les cellules endothéliales vasculaires est mal compris. Dans une première partie de ce travail, le rôle de la longueur de PEG sur l'endocytose et la transcytose des NPs a été étudié sur des monocouches de cellules bEnd.3, un modèle in vitro de BHE. Les mécanismes de transport des NPs ont été évalués en utilisant différents inhibiteurs de l'endocytose. La quantification du taux d'endocytose et de transcytose a révélé que l'endocytose et la transcytose des NPs augmentaient avec la longueur de la chaîne de PEG. Les taux d'endocytose et de transcytose les plus élevés ont été observés pour les NPs de PLA-PEG5000 et de PLA-PEG10000. Les résultats de l’étude mécanistique démontrent que la longueur de la chaîne de PEG influence la voie d'endocytose empruntée par les NPs PEGylées à travers un modèle in vitro de BHE. Dans une seconde partie de ce travail, l'effet de la longueur du PEG sur la toxicité des NPs et les processus inflammatoires a été étudié sur deux modèles de monocouche de cellules endothéliales vasculaires, soit les cellules bEnd.3 et HUVEC. L'effet de la longueur des chaînes de PEG sur l'expression des gènes impliqués dans la réponse inflammatoire aux NPs PEGylées a été évalué par qPCR. De plus, le potentiel de génération de dérivés réactifs de l'oxygène (DRO ou ROS) par les NPs a été évalué en utilisant le test cellulaire basé sur l'oxydation de la DCFH-DA. Les résultats démontrent que les NPs PEGylées induisent une augmentation légère et transitoire de l’expression des gènes des cytokines et des chimiokines inflammatoires. Cependant, la longueur des chaînes de PEG ne présente pas un effet significatif sur l'expression des gènes des cytokines et des chimiokines. De plus, nos résultats ne montrent pas l’induction de la génération de ROS par les NPs PEGylées. En résumé, la longueur de chaine de PEG influence le taux d’endocytose et de transcytose. La voie d’endocytose impliquée dans l’internalisation et la transcytose est influencée par la longueur des chaines de PEG. En revanche, les différences de longueur des chaines de PEG ne modulent pas significativement l’expression des cytokines et de chimiokines inflammatoires. Ces résultats devraient contribuer à développer des nanoformulations qui traversent plus efficacement la BHE, tout en minimisant les effets toxiques, notamment inflammatoires sur les cellules endothéliales vasculaires de la BHE. Ces perspectives devront toutefois être confirmées sur des modèles in vivo. / To date, imaging and treatment of brain tumors are proved to be very inefficient due to the presence of the blood-brain barrier (BBB). The (BBB) is a semipermeable barrier which prevents or restrains most therapeutic and diagnostic molecules reach the central nervous system (CNS). Polymeric nanoparticles (NPs) loaded by therapeutics molecules and diagnostic agents could represent a promising solution to help active ingredients to cross the BBB and as a consequence, their biodistribution to the brain could be improved. Polymeric NPs composed of di-block copolymers, such as poly (ethylene glycol) blocks (PEG) that bind to polyester hydrophobic chains, are considered one of the most versatile nanocarriers for transporting therapeutic molecules across the BBB. PEG on the surface of NPs improves the NPs colloidal stability. Furthermore, PEG surface coating decreases the non-specific adsorption of proteins on the surface of NPs (also called opsonization); therefore, the clearance rate of the NPs is slowed down and NPs circulation times in blood is extended. Despite the beneficial effect of the PEG coating on the surface of NPs, the exact role of the surface properties related to the PEG chain length on NPs interactions with the vascular endothelial cells is poorly understood. In first article, the role of PEG chain length on brain vascular endothelial cells endocytosis and transcytosis is investigated on monolayers of bend.3 cells as an in vitro BBB model. The NPs transport mechanisms were then investigated by using different endocytosis inhibitory processes. Our results revealed that NPs endocytosis and transcytosis rates increased with PEG chain length. Higher endocytosis and transcytosis rates were observed for PLA-PEG5000 and PLA-PEG10000 NPs. Moreover, the mechanistic studies demonstrated that the PEG chain length influenced the endocytosis pathway taken by PEGylated NPs through an in vitro model of BBB. In second article, the effect of PEG length on NPs cytotoxicity and inflammatory processes has been investigated in two vascular endothelial cell lines (bEnd.3 and HUVEC). The effect of PEG chain length coating on gene expression that are involved in the inflammation response was investigated by qPCR. Moreover, the potential Reactive Oxygen Species (ROS) generation was evaluated with DCFH-DA probe. The results showed that PEGylated NPs induce a mild and transient activation of inflammatory cytokine and chemokine genes. However, the length of the PEG chains did not modulate significantly gene expression of inflammatory cytokines and chemokines. Furthermore, our results showed that PEGylated NPs did not induce ROS generation. In summary, the chain length of PEG influences the endocytosis and transcytosis rate. The pathway of endocytosis involved in internalization and transcytosis is influenced by the length of PEG chains. In contrast, differences in the length of PEG chains did not significantly modulate the expression of cytokines and inflammatory chemokines. These results contribute to develop nanoformulations that cross the BBB more efficiently while keeping the toxic and inflammatory effects minimal, particularly on the vascular endothelial cells of the BBB. Nevertheless, these perspectives have to be confirmed on in vivo models.
322

Identification of pathways in liver repair potentially targeted by secretory proteins from human mesenchymal stem cells

Winkler, Sandra, Hempel, Madlen, Brückner, Sandra, Tautenhahn, Hans-Michael, Kaufmann, Roland, Christ, Bruno January 2016 (has links)
Background: The beneficial impact of mesenchymal stem cells (MSC) on both acute and chronic liver diseases has been confirmed, although the molecular mechanisms behind it remain elusive. We aim to identify factors secreted by undifferentiated and hepatocytic differentiated MSC in vitro in order to delineate liver repair pathways potentially targeted by MSC. Methods: Secreted factors were determined by protein arrays and related pathways identified by biomathematical analyses. Results: MSC from adipose tissue and bone marrow expressed a similar pattern of surface markers. After hepatocytic differentiation, CD54 (intercellular adhesion molecule 1, ICAM-1) increased and CD166 (activated leukocyte cell adhesion molecule, ALCAM) decreased. MSC secreted different factors before and after differentiation. These comprised cytokines involved in innate immunity and growth factors regulating liver regeneration. Pathway analysis revealed cytokine-cytokine receptor interactions, chemokine signalling pathways, the complement and coagulation cascades as well as the Januskinase-signal transducers and activators of transcription (JAK-STAT) and nucleotide-binding oligomerization domain-like receptor (NOD-like receptor) signalling pathways as relevant networks. Relationships to transforming growth factor beta(TGF-beta) and hypoxia-inducible factor 1-alpha (HIF1-alpha) signalling seemed also relevant. Conclusion: MSC secreted proteins, which differed depending on cell source and degree of differentiation. The factors might address inflammatory and growth factor pathways as well as chemo-attraction and innate immunity. Since these are prone to dysregulation in most liver diseases, MSC release hepatotropic factors, potentially supporting liver regeneration.
323

Rôle des inhibiteurs de PARP en association avec le carboplatine dans l’inhibition des métastases dans le cancer du sein triple négatif

Hubert, Audrey 10 1900 (has links)
Le cancer du sein triple négatif (CSTN) est un sous-type de cancer du sein très agressif et dépourvu de surexpression des récepteurs hormonaux et de HER2. Les tumeurs mutantes BRCA1 et BRCA2 constituent 15 à 20% des CSTN et récemment un groupe d’agent thérapeutique ciblé prometteur a vu le jour pour ce type de cancers. En effet, les inhibiteurs de PARP (PARPi) ont démontré une amélioration de la survie sans maladie à distance chez les patientes atteintes d'un cancer du sein précoce avec mutation BRCA1/2 HER2 négatif, suggérant que les PARPis peuvent éliminer la maladie micrométastatique. Cependant, des réponses plus durables seront probablement obtenues si les PARPis sont utilisés en combinaison, comme avec un autre agent endommageant l'ADN tout comme le carboplatine. De plus, il est plausible que l'efficacité puisse être améliorée et la toxicité diminuée si un PARPi puissant comme le talazoparib est administré en utilisant une approche séquentielle. Ici, nous avons évalué l'impact des stratégies de dosage concomitantes et séquentielles dans des lignées cellulaires du CSTN et trois modèles de souris de xénogreffe orthotopique. Alors que la combinaison simultanée ou séquentielle ont inhibé les volumes tumoraux primaires de la même manière, la combinaison séquentielle a diminué la migration, l'invasion, les métastases à distance et a été associée à moins de toxicité. Par conséquent, ces combinaisons du talazoparib et du carboplatine devraient être considérées dans les futurs essais cliniques comme une approche efficace pour inhiber la maladie micrométastatique et potentiellement diminuer l'utilisation de la chimiothérapie chez ces patients. / The triple-negative breast cancer (TNBC) is a very aggressive breast cancer subtype that lacks overexpression of hormone receptors and HER2. BRCA1 and BRCA2 mutant tumors constitute 15-20% of TNBC and recently, a family of promising targeted therapeutic agents has emerged for this type of cancer. Indeed, PARP inhibitors (PARPi) have been shown to improve distant disease-free survival in patients with HER2-negative BRCA1/2 mutation early breast cancer, suggesting that PARPis can eliminate micrometastatic disease. However, durable responses are likely to be obtained if PARPis are used in combination, such as with another DNA damaging agent like carboplatin. Additionally, it is plausible that efficacy may be enhanced and toxicity decreased if a potent PARPi such as talazoparib is administered using a sequential approach. Here, we evaluated the impact of the concomitant and sequential dosing strategies in TNBC cell lines and three orthotopic xenograft mouse models. While the simultaneous or sequential combination inhibited primary tumor volumes to a similar extent, the sequential combination decreased migration, invasion, distant metastasis, and was associated with less toxicity. Therefore, the sequential combination of talazoparib and carboplatin should be considered in future clinical trials as an effective approach to inhibit micrometastatic disease and potentially decrease the use of chemotherapy in these patients.
324

The effects of solar irradiated Salmonella Typhimurium and campylobacter jejuni on the proliferation and activation of macrophages in vitro

Chihomvu, Patience 12 1900 (has links)
D. Tech. (Department of Biotechnology, Faculty of Applied and Computer Sciences), Vaal University of Technology. / Salmonella enterica serovar Typhimurium and Campylobacter jejuni are the leading causes of Salmonellosis and Campylobacteriosis that is characterised by gastroenteritis. These waterborne diseases can be easily prevented by home water treatment methods such as solar disinfection (SODIS). The SODIS process involves placing microbiologically unsafe water in clear plastic or glass bottles and exposing them to direct sunlight for approximately six to eight hours. SODIS kills microbes through a combination of DNA-damaging effects of ultraviolet (UV) radiation and thermal inactivation from solar heating. The result is microbiologically safe water. Continuous drinking of SODIS treated water may confer some immunological effects on the consumer. These immunological effects have not been thoroughly explored. Therefore, the objectives of this study were to firstly, characterise the effects of solar irradiation on the viability of S. Typhimurium and C. jejuni; secondly, to determine the cytotoxicity and modulation of cell death of solar irradiated S. Typhimurium and C. jejuni on macrophages. Thirdly, to analyse the chemokine and cytokine profiles of macrophages infected with solar irradiated S. Typhimurium and C. jejuni. Lastly, to analyse the host-cell interactions of macrophages infected with solar-irradiated and non-solar irradiated S. Typhimurium and C. jejuni using a proteomic approach. In all the experiments, S. Typhimurium and C. jejuni were (i) heat/chemically treated, (ii) solar and non-solar irradiated for 4 and 8 hours. A murine macrophage cell line RAW264.7 was co-cultured with the differentially treated bacteria species for 3 and 24 hours. Appropriate controls were included. The impact of solar irradiated S. Typhimurium and C. jejuni on intracellular growth, proliferation, cytotoxicity, and apoptosis on macrophages was assessed. Intracellular growth of the both bacterial species was assessed with the gentamicin protection assay, and cytotoxicity was determined by Lactate Dehydrogenase Assay (LDH). The macrophages treated with solar irradiated S. Typhimurium and C. jejuni showed no intracellular growth after 48 hours post-infection. However, the non-irradiated S. Typhimurium survived within the macrophages and were highly toxic to the macrophages (average cytotoxicity of 91%±32). The non-solar irradiated C. jejuni were metabolically active but non-culturable, whereas the solar-irradiated C. jejuni was metabolically inactive. Thus, solar irradiated C. jejuni showed a lower percentage cytotoxicity (2.57% ± 0.32%) in comparison to non-solar irradiated C. jejuni at 24 hours post-infection (p.i.) (30.28% ± 0.05%). Flow cytometric analysis showed that the non-irradiated S. Typhimurium brought about a statistically significant increase in the percentage of necrotic cells (48% ± 2.99%), whereas bacteria irradiated for 8 hours produced a lower percentage of necrotic cells (25% ± 5.87%). The heat/chemical attenuated samples had the lowest percentage of necrotic cells (21.15% ± 5.36%) at 24 h p.i. Macrophages treated with solar irradiated and non-solar irradiated C. jejuni did not induce necrosis, but apoptotic cell death. At 24 h p.i., the highest proportion of apoptotic cell death was observed in macrophages treated with non-solar irradiated C. jejuni whereas the solar irradiated C. jejuni showed a lower percentage of apoptotic cell death. Therefore, there is great possibility that S. Typhimurium and C. jejuni could become avirulent after SODIS treatment and this could prevent gastroenteritis in consumers of SODIS-treated water. The activation of macrophages infected with solar irradiated S. Typhimurium and C. jejuni was also assessed in this study. The production of nitric oxide (NO) was determined using the Greiss Reagent Assay, whereas the production of chemokines, cytokines, and growth stimulating factors by the RAW264.7 cells in vitro was measured using the Luminex 200. The results showed that both solar and non-solar irradiated S. Typhimurium inhibited the production of nitric oxide in the RAW264.7 cells. The heat/chemically attenuated S. Typhimurium induced a significant increase (p<0.0.5) in the production of NO2− in the macrophages when compared to the unstimulated RAW264.7. The chemokine and cytokine levels produced by the macrophages were similar in the solar inactivated S. Typhimurium and the live untreated S. Typhimurium. However, macrophages treated with heat/chemically attenuated S. Typhimurium showed an anti-inflammatory response by inhibiting the production of pro-inflammatory cytokines such as IL-1, IL-1, IL-2, IL-6, and IL-17 in macrophages. The macrophages treated with solar and non-solar irradiated C. jejuni possibly produced an anti-inflammatory effect since the amount of pro-inflammatory cytokines in the samples was significantly reduced during the late infection period (24 h p.i.). This study also analysed the proteomic profiles of macrophages treated with LPS, non-solar irradiated, solar irradiated, heat/ chemical inactivated S. Typhimurium, and C. jejuni. This was carried out using SWATH-mass spectrophotometry-based proteomics. Proteins were extracted from infected macrophages after 24 hours p.i. HILIC-based sample clean-up and digestion, DDA LCMS-MS (spectral library), SWATH LCMS-MS, and data processing were carried out. A total of 15,077 peptides matching to 2,778 proteins were identified at 1% FDR with numerous differentially expressed proteins (DEPs) detected in macrophages treated with lipopolysaccharide (LPS), non-solar irradiated C. jejuni (NS), heat-attenuated C. jejuni (HA) and 4h-solar irradiated (SI4) and 8h-solar irradiated (SI8) C. jejuni, respectively. Pathway analysis revealed that most of the upregulated proteins in macrophages treated with solar irradiated C. jejuni were involved in oxidation-reduction processes, endoplasmic reticulum stress, transport, antigen processing and presentation of exogenous peptide antigens via MHC class I (TAP-dependant) and ATP-biosynthetic processes. The KEGG-pathways also revealed the roles of some upregulated proteins in lysosomal and phagosome pathways. In conclusion, our results revealed that there is coordinated up-regulation of MHC-I processing pathways occurred at 24 h p.i. It is likely that proteins from solar irradiated C. jejuni may undergo proteasomal degradation, and the peptides are transported to the endoplasmic reticulum (ER) and loaded onto MHC-I molecules. Peptide loading results in class I complexes consolidation and transit to the cell surface where antigens can be presented to circulating CD8 + T cells. Additionally, solar irradiated C. jejuni also undergoes degradation in the phagosome. The phagosome has the potential to create antigens that can be expressed on the cell surface of macrophages to stimulate different lymphocytes and induce appropriate immune responses, thus, connecting the innate to adaptive immunity, and this could also have health benefits via the consumption of SODIS treated water. However, proteomic analysis of S. Typhimurium showed no significant differentially expressed proteins in macrophages treated with LPS, non-solar irradiated, and solar irradiated S. Typhimurium. This may be due to an overestimation of the extracted protein. However, DEPs in macrophages treated with heat-attenuated S. Typhimurium showed that macrophages may have adapted an anti-inflammatory M2 phenotype because the IFN-γ signalling pathway was downregulated. This may have contributed to non-expression of the chemokine IFN-γ in RAW264.7 cells. Moreover, proteins such as Hmox1 and Sqstm1 were upregulated, and this is also characteristic of M2 macrophages. This study provided new insights on the effect of solar irradiated Salmonella Typhimurium and Campylobacter jejuni on the proliferation and activation of macrophages in vitro.
325

Increased Bacterial Adherence and Decreased Bacterial Clearance in Urinary Tract Infections with Diabetes Mellitus

Ozer, Ahmet 23 August 2013 (has links)
No description available.
326

Differential effects of stress on the immune response to influenza A/PR8 virus infection in mice

Hunzeker, John T. 19 May 2004 (has links)
No description available.
327

Analyse der Expression von Chemokinen und Chemokinrezeptoren in HNO-Tumorzellen unter Radiochemotherapie / Analysis of chemokine and chemokine receptor expression in squamous cell carcinoma of the head and neck cell lines

Holzer, Claudia Anna 13 March 2017 (has links)
No description available.
328

Rôle des cellules endothéliales dans l’immunité innée précoce induite lors d’infections par des coronavirus murins

Bleau, Christian 08 1900 (has links)
Les cellules endothéliales (EC) constituent une première barrière physique à la dissémination de virus pléiotropiques circulant par voie hématogène mais leur contribution à la défense innée anti-virale est peu connue. Des dysfonctions des EC de la barrière hémato-encéphalique (BMEC) et des sinusoïdes hépatiques (LSEC) ont été rapportées dans des neuropathologies et des hépatites aiguës ou chroniques d’origine virale, suggérant que des atteintes à leur intégrité contribuent à la pathogenèse. Les sérotypes de coronavirus de l’hépatite murine (MHV), se différenciant par leur capacité à induire des hépatites et des maladies neurologiques de sévérité variable et/ou leur tropisme pour les EC, représentent des modèles viraux privilégiés pour déterminer les conséquences de l’infection des EC sur la pathogenèse virale. Lors d’infection par voie hématogène, le sérotype MHV3, le plus virulent des MHV, induit une hépatite fulminante, caractérisée par une réponse inflammatoire sévère, et des lésions neurologiques secondaires alors que le sérotype moins virulent, MHV-A59, induit une hépatite modérée sans atteintes secondaires du système nerveux central (SNC). Par ailleurs, le sérotype MHV3, à la différence du MHV-A59, démontre une capacité à stimuler la production de cytokines par la voie TLR2. Les variants atténués du MHV3, les virus 51.6-MHV3 et YAC-MHV3, sont caractérisés par un faible tropisme pour les LSEC et induisent respectivement une hépatite modérée et subclinique. Compte tenu de l’importance des LSEC dans le maintien de la tolérance hépatique et de l’élimination des pathogènes circulants, il a été postulé que la sévérité de l’hépatite et de la réponse inflammatoire lors d’infections par les MHV est associée à la réplication virale et à l’altération des propriétés tolérogéniques et vasculaires des LSEC. Les désordres inflammatoires hépatiques pourraient résulter d’une activation différentielle du TLR2, plutôt que des autres TLR et des hélicases, selon les sérotypes. D’autre part, compte tenu du rôle des BMEC dans la prévention des infections du SNC, il a été postulé que l’invasion cérébrale secondaire par les coronavirus est reliée à l’infection des BMEC et le bris subséquent de la barrière hémato-encéphalique (BHE). À l’aide d’infections in vivo et in vitro par les différents sérotypes MHV, chez des souris ou des cultures de BMEC et de LSEC, nous avons démontré, d’une part, que l’infection in vitro des LSEC par le sétotype MHV3, à la différence des variants 51.6- et YAC-MHV3, altérait la production du facteur vasodilatant NO et renversait leur phénotype tolérogénique en favorisant la production de cytokines et de chimiokines inflammatoires. Ces dysfonctions se traduisaient in vivo par une réponse inflammatoire incontrôlée et une dérégulation du recrutement intrahépatique de leucocytes, favorisant la réplication virale et les dommages hépatiques. Nous avons aussi démontré, à l’aide de souris TLR2 KO et de LSEC dont l’expression du TLR2 a été abrogée par des siRNA, que la sévérité de l’hépatite et de la réponse inflammatoire induite par le sérotype MHV3, dépendait en partie de l’induction et de l’activation préférentielle du TLR2 par le virus dans le foie. D’autre part, la sévérité de la réplication virale au foie et des désordres dans le recrutement leucocytaire intrahépatique induits par le MHV3, et non par le MHV-A59 et le 51.6-MHV3, corrélaient avec une invasion virale subséquente du SNC, au niveau de la BHE. Nous avons démontré que l’invasion cérébrale du MHV3 était associée à une infection productive des BMEC et l’altération subséquente des protéines de jonctions serrées occludine, VE-cadhérine et ZO-1 se traduisant par une augmentation de la perméabilité de la BHE et l’entrée consécutive du virus dans le cerveau. Dans l’ensemble, les résultats de cette étude mettent en lumière l’importance du maintien de l’intégrité structurale et fonctionnelle des LSEC et des BMEC lors d’infections virales aigües par des MHV afin de limiter les dommages hépatiques associés à l’induction d’une réponse inflammatoire exagérée et de prévenir le passage des virus au cerveau suite à une dissémination par voie hématogène. Ils révèlent en outre un nouveau rôle aggravant pour le TLR2 dans l’évolution de l’hépatite virale aigüe ouvrant la voie à de nouvelles avenues thérapeutiques visant à moduler l’activité inflammatoire du TLR2. / Endothelial cells (EC) act as a physical barrier against invasion by pleiotropic blood borne viruses but their contribution in innate antiviral defense is poorly known. Dysfunctions in blood-brain barrier EC (BMECs) and liver sinusoidal EC (LSECs) have been reported in viral neuropathologies and hepatitis, suggesting that loss of ECs integrity may contribute to the pathogenesis. Mouse hepatitis coronaviruses (MHV), differing in their ability to induce severe to subclinical hepatitis and neurological diseases and / or their tropism for ECs, are relevant viral models to study the consequences of EC infection in viral pathogenesis. Following hematogenous infection, the MHV3 serotype, the most virulent MHV, induces fulminant hepatitis, characterized by severe inflammatory response, followed by neurological damage whereas the less virulent MHV-A59 serotype induces milder hepatitis but does not invade the central nervous system (CNS). In addition, MHV3, in contrast to MHV-A59, shows ability to induce TLR2-dependent cytokine response. The attenuated MHV3 variants, 51.6-MHV3 and YAC-MHV3, are characterized by a weak tropism for LSECs and induce moderated and subclinical hepatitis respectively. Given the importance of LSECs in hepatic tolerance and the elimination of circulating pathogens, it has been postulated that the severity of hepatitis and inflammatory response induced by MHVs correlates with infection and alterations in vascular and tolerogenic properties of LSECs. Hepatic inflammatory disorders may result from differential activation of TLR2, rather than other TLRs and helicases, according to serotypes. Moreover, given the role of BMECs in preventing CNS infections, it has been postulated that secondary cerebral invasion by coronaviruses is related to infection of BMECs and subsequent breakdown of the blood-brain barrier (BBB). Through in vitro and in vivo infections of isolated BMECs, LSECs or mice with the different MHVs, we demonstrated, first, that in vitro productive infection of LSECs by the highly virulent MHV3 serotype, in contrast to 51.6- et YAC-MHV3 variants, altered their production of vasoactive factors and overthrew their intrinsic tolerogenic properties by promoting inflammatory cytokines and chemokines production. These disturbances were reflected in vivo by an uncontrolled inflammatory response and a deregulation of intrahepatic leukocyte recruitment, favoring viral replication and liver damages. We demonstrated, using TLR2 KO mice and LSECs treated with siRNA for TLR2 that the abnormal inflammatory response induced by MHV3 depended in part on preferential induction and activation of TLR2 by the virus on the surface of hepatic cells. Moreover, the severity of the primary viral replication in the liver and disorders in intrahepatic leucocyte recruitment induced by MHV3, but not by MHV-A59 and 51.6-MHV3, correlated with a subsequent brain invasion at the BBB level. Such invasion was related to productive infection of BMECs and subsequent IFN--dependent disruption of tight junction proteins occludin, VE-cadherin and ZO-1, resulting in an increase of BBB permeability and further viral entry into the CNS. Overall, the results of this study highlight the importance of structural and functional integrity of LSECs and BMECs during acute viral infections by MHVs to limit liver damages associated with viral-induced exacerbation of inflammatory response and prevent brain invasion by MHVs following viral spread through the bloodstream. They also reveal a new worsening role for TLR2 in the evolution of acute viral hepatitis paving the way for new therapies targeting TLR2-induced inflammatory activity.
329

Avaliação dos biomarcadores urinários de inflamação e de remodelação tecidual na disfunção vesical em pacientes com hiperplasia prostática benigna / Evaluation of urinary biomarkers of inflammation and tissue remodeling in bladder dysfunction in patients with benign prostatic hyperplasia

Conti, Paulo Sajovic de 08 February 2019 (has links)
INTRODUÇÃO: A HD está presente em aproximadamente 50% dos pacientes com OIV devido HPB e 30% dos casos não apresentarão melhora após o tratamento cirúrgico. Até o momento, nenhuma característica clínica pode predizer acuradamente quais pacientes serão beneficiados. Há espaço para o aprimoramento de novos métodos diagnósticos não invasivos capazes de discriminar quais os melhores candidatos à cirurgia. Neste estudo nós analisamos o papel de cinco biomarcadores urinários moleculares associados à HD e à OIV em pacientes com HPB que serão submetidos à RTUP. MÉTODOS: Um estudo prospectivo e controlado analisou 71 pacientes candidatos à RTUP devido HPB, submetidos ao procedimento cirúrgico entre 2011 a 2016. O grupo controle foi composto por pacientes assintomáticos apresentando IPSS menor que 6, volume prostático menor que 30 gramas, ausência de resíduo pósmiccional e fluxometria máxima >= 15ml/s. Todos os pacientes do grupo de estudo realizaram estudo urodinâmico no pré-operatório e 63 pacientes no período pósoperatório. Nós analisamos a presença, o período de início (primeira vs segunda metade do enchimento vesical) e a amplitude ( 40 cmH2O) das CVIs, assim como o grau de obstrução infravesical. A coleta da urina foi realizada no pré-operatório para os pacientes do grupo de estudo. A urina foi analisada para 5 quimiocinas, citocinas e fatores de crescimento usando teste de ELISA. Os valores de concentração das proteínas foram analisados de forma absoluta e normalizados para os níveis de creatinina (/Cr). RESULTADOS: A idade média dos pacientes foi 67 anos (50 a 88). A HD estava presente em 39 (54,9%) pacientes. De acordo com aferições pré-operatórias, a média da concentração urinária de IL-6/Cr (p=0,007), MCP-1(p=0,000), MCP-1/Cr (p=0,000), EFG/Cr (p=0,044) e MMP-1/Cr (p=0,043) estavam respectivamente cerca de 4,5x, 7,1x, 23x, 1,7x e 2,2x vezes significativamente aumentadas em relação aos controles assintomáticos. O nível de EGF foi 1,3 vezes maior nos pacientes que iniciaram CVI tardiamente quando comparados àqueles que iniciaram as contrações na fase inicial de enchimento vesical (p=0,044). A amplitude das CVIs, o fluxo urinário, a complacência, o índice de contratilidade, e o schafer não apresentaram correlações estatísticas com as proteínas estudadas. Em relação a presença de HD, os níveis urinários de IL-6 (p=0,003), MCP-1(p=0,002), e MCP-1/Cr (p=0,002) foram respectivamente 1,8x, 2x, e 2,7 vezes aumentados em relação aos pacientes submetidos à cirurgia sem HD ao estudo urodinâmico. O MCP-1/Cr foi o marcador com melhores propriedades diagnósticas para HD, apresentando área sob a curva (AUC) de 0,71 (95% CI 0,59 a 0,84). A dosagem do MCP-1 não ajustada pela creatinina apresentou uma AUC de 0,71 (95% CI 0,59 a 0,83). A IL-6, por sua vez, teve uma AUC de 0,70 (95% CI 0,58 a 0,82). Todos os outros biomarcadores apresentaram propriedades inadequadas neste cenário para avaliação da HD e OIV. Em relação à resolução ou persistência da HD após 12 meses de tratamento cirúrgico, os níveis dos biomarcadores NGF/Cr (p=0.005) e MMP-1/Cr (p=0.021) foram superiores entre os pacientes que não obtiveram interrupção das CVIs no pós-operatório. Demonstraram serem úteis para predizer a persistência da HD no pós-operatório, o NGF/Cr com AUC de 0,77 (95% CI 0,62 à 0,92) (p=0,006) e o MMP-1/Cr com AUC de 0,72 (95% CI 0,56 à 0,88) (p=0,022). CONCLUSÕES: Vias neuronais parecem estar relacionadas com o período de início das CVIs durante a fase de enchimento vesical. A presença de níveis elevados na urina de biomarcadores inflamatórios e de reparo tecidual sugere um papel da inflamação na gênese da HD, e pode ajudar no diagnóstico não invasivo deste achado no pré-operatório. MCP-1, MCP-1 /Cr e IL-6 foram associados a presença de de HD ao estudo urodinâmico em pacientes com HPB candidatos a RTUP. O nível de EGF/Cr foi associado a contrações vesicais tardias. O MMP-1/Cr foi relacionado a maior pressão detrusora. O biomarcador MCP-1/Cr demonstrou-se ser útil no diagnóstico de HD nos pacientes com HPB. NGF/Cr e MMP-1/Cr demonstraram-se ser úteis para predizer a persistência da HD no pós-operátorio / INTRODUCTION: Detrusor hyperactivity (DH) is present in approximately 50% of patients with bladder outlet obstruction (BOO) due to benign prostatic hyperplasia (BPH), and 30% of the cases will not show improvement after surgical treatment. To date, no clinical feature can accurately predict which patients will benefit from surgical treatment. This rate can be improved because new noninvasive diagnostic methods are capable of determining the best candidates for surgery. In this study, we analyzed the role of five molecular biomarkers in urine associated with DH and BOO in patients with BPH undergoing transurethral resection of the prostate (TURP). METHODS: This prospective and controlled study analyzed 71 patients who were candidates for TURP due to BPH and underwent surgery between 2011 and 2016. The control group consisted of asymptomatic patients with International Prostate Symptom Scores (IPSSs) less than 6, prostate volume less than 30 grams, absence of estimated postvoid residual volume and a maximum flow rate >= 15 ml/s. All patients in the study group underwent a preoperative urodynamic study, with 63 patients undergoing a repeat urodynamic study during the postoperative period. We analyzed the presence, onset period (first vs second half of bladder filling) and amplitude ( 40 cmH2O) of the involuntary detrusor contractions (IDCs), as well as the degree of BOO. Urine was collected preoperatively from patients in the study group. The urine was analyzed for five chemokines, cytokines and growth factors using ELISAs. The protein concentrations were analyzed as absolute and creatinine (/Cr)-adjusted values. RESULTS: The mean age of the patients was 67 years (50 to 88). DH was present in 39 (54.9%) patients. According to preoperative measurements, the mean urine concentrations of IL-6/Cr (p = 0.007), MCP-1 (p = 0.000), MCP-1/Cr (p = 0.000), EGF/Cr (p = 0.044) and MMP-1/Cr (p = 0.043) were approximately 4.5, 7.1, 23, 1.7 and 2.2 times, respectively, those of asymptomatic controls (all significantly increased). The EGF level was 1.3 times higher in patients with late IDCs than in those whose contractions started in the early stage of bladder filling (p = 0.044). The IDC amplitude, urinary flow, compliance, bladder contractility index, and Schafer\'s grade were not significantly correlated with the proteins studied. In patients with DH, urinary levels of IL-6 (p = 0.003), MCP-1 (p = 0.002), and MCP- 1/Cr (p = 0.002) were 1.8, 2, and 2.7 times higher, respectively, than in patients without DH who underwent surgery, according to the urodynamic study. MCP- 1/Cr had the best diagnostic properties for DH, with an area under the curve (AUC) of 0.71 (95% CI: 0.59 to 0.84). The non-Cr adjusted MCP-1 concentration had an AUC of 0.71 (95% CI: 0.59 to 0.83). Additionally, IL-6 had an AUC of 0.70 (95% CI: 0.58 to 0.82). All other biomarkers were inadequate for DH and BOO evaluation. Regarding the resolution or persistence of DH 12 months after surgery, the NGF/Cr (0.13 vs 0.08, p = 0.005) and MMP-1/Cr (0.11 vs 0.04, p = 0.021) levels were higher in patients for whom the IDCs continued during the postoperative period. The following factors were shown to be useful for predicting the persistence of DH during the postoperative period: NGF/Cr, with an AUC of 0.77 (95% CI: 0.62 to 0.92) (p = 0.006), and MMP-1/Cr, with an AUC of 0.72 (95% CI: 0.56 to 0.88) (p = 0.022). CONCLUSIONS: Neural pathways appear to be related to the onset period of IDCs during bladder filling. The presence of high urinary levels of inflammatory and tissue repair biomarkers suggests a role of inflammation in the genesis of DH and may aid in the noninvasive diagnosis of this condition during the preoperative period. MCP-1, MCP-1/Cr and IL-6 were associated with the presence of DH in the urodynamic studies of patients with BPH who were candidates for TURP. The EGF/Cr level was associated with late detrusor contractions. MMP-1/Cr was associated with increased detrusor pressure. The MCP-1/Cr biomarker was shown to be useful for the diagnosis of DH in patients with BPH. NGF/Cr and MMP-1/Cr were shown to be useful in predicting the persistence of DH during the postoperative period
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Darmschädigung durch Photonen-Strahlung nach Einzeitbestrahlung der Leber / Radiation-induced damage in different segments of the rat intestine after external

Schwartz, Antonia 16 January 2012 (has links)
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