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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.
61

Effets anti-inflammatoires de l'inhibiteur dépendant de la protéine Z : intérêt potentiel comme traitement adjuvant du sepsis / Anti-inflammatory effects of Protein Z-dependent protease inhibitor (ZPI) : potential benefit on sepsis adjuvant therapy

Razanakolona, Mahita 20 December 2018 (has links)
Le choc septique est une défaillance circulatoire aiguë déclenchée par un agent infectieux, entraînant des désordres hémodynamiques, métaboliques et viscéraux, en raison notamment de la libération de cytokines proinflammatoires. Le taux de mortalité est élevé (environ 40 %). L’évolution des sepsis sévères est souvent compliquée par des phénomènes thrombotiques qui résultent en partie de l’activation de la coagulation par les agents infectieux, mais aussi de la libération de Neutrophil Extracellular Traps (NETs) par les polynucléaires neutrophiles. Ainsi, chez ces patients, une coagulation intravasculaire disséminée (CIVD) est souvent observée, caractérisée par un état d’équilibre instable, où co-existent un risque thrombotique et un risque hémorragique, dû à la consommation des facteurs de coagulation.Plusieurs études ont suggéré que l’administration d’antithrombine (AT) ou de Protéine C activée diminuait la mortalité, non seulement en diminuant l’activation de la coagulation, mais aussi en ayant des effets cytoprotecteurs et anti-inflammatoires indépendants de leur activité anti-coagulante. Toutefois, leurs effets cytoprotecteurs nécessitent l’administration de doses élevées, responsables d’hémorragies.L’inhibiteur dépendant de la protéine Z (ZPI), appartient à la superfamille des serpines, comme l’AT, mais n’inhibe que les facteurs Xa (FXa) et XIa (FXIa). L’inhibition du FXa est potentialisée par la Protéine Z (PZ), un facteur vitamine K-dépendant, qui circule dans le plasma lié au ZPI. Dans un modèle en sang total, j’ai observé que le ZPI exerce un effet inhibiteur sur la production de cytokines pro-inflammatoires (IL-6 et TNF-α) en réponse au lipopolysaccharide (LPS). A forte concentration (4 fois la concentration physiologique), l’effet anti-inflammatoire (EAI) du ZPI n’est pas modifié par l’ajout de PZ ou d’héparine non fractionnée, qui majorent l’effet anticoagulant du ZPI. De plus, l’EAI persiste avec un variant de ZPI muté sur son site actif (ZPI Y387A), suggérant que le ZPI possède un EAI indépendant de son activité anticoagulante. In vitro, en sang total, le ZPI augmente précocement la production de CCL-5, une chimiokine ayant des propriétés anti-inflammatoires. Ces observations ont été confirmées dans un modèle d’endotoxinémie in vivo, chez la souris, en injectant par voie intra-péritonéale du LPS. Les souris qui avaient reçu simultanément du ZPI recombinant humain ont un taux plasmatique plus faible d’IL-6 et de TNF α que les souris contrôles et un taux plus élevé de CCL-5 dans le lavage péritonéal.De plus, nous avons mis en évidence, en milieu purifié, que l’élastase neutrophile, une enzyme libérée à la surface des NETs induisait plusieurs clivages du ZPI. Le premier clivage se produit au niveau de la boucle réactive du ZPI, qui perd alors son activité inhibitrice sur les FXa et FXIa. La PZ ne protège pas le ZPI de sa dégradation par l’élastase. La dégradation du ZPI induite par les NETs pourrait participer à leurs propriétés procoagulantes.Enfin, en collaboration avec l’équipe du Service de Réanimation du CHU de Strasbourg, nous avons étudié les variations des taux plasmatiques de PZ et ZPI chez 100 patients atteints de sepsis sévère. Dans les premières 24 heures, nous avons observé une diminution du taux de PZ par rapport à une groupe de sujets sains, et à l’inverse, une augmentation d’environ 2,5 fois du taux de ZPI. Ce taux élevé de ZPI persiste à J3 et J7, alors que le taux de PZ augmente. Les variations de PZ ou ZPI ne sont pas prédictifs de la mortalité à 30 jours ni de l’apparition d’une CIVD.Ces résultats suggèrent que des doses élevées de ZPI (4 fois la concentration physiologique) pourraient constituer un traitement adjuvant du choc septique, en diminuant la production de cytokines pro-inflammatoires, avec un risque hémorragique faible, puisque l’inhibition du FXIa a des activités antithrombotiques dépourvues de risque hémorragique. / Septic shock is an acute circulatory failure caused by an infectious agent, resulting in hemodynamic, metabolic and visceral disorders, in particular due to pro-inflammatory cytokines. The mortality rate is high (about 40 %). Progression of severe sepsis is often complicated by thrombotic events, in part because of a direct coagulation activation by bacteria, but also because of Neutrophil Extracellular Traps (NETs) released by polymorphonuclear neutrophils. Disseminated intravascular coagulation (DIC) is frequently present in these patients, characterized by an unstable equilibrium, where thrombotic and bleeding risks coexist, due to the consumption of coagulation factors.Several studies suggested that administration of coagulation inhibitors, such as antithrombin (AT) or activated Protein C, decreased mortality, not only by preventing the activation of coagulation, but also through their cytoprotective and anti-inflammatory effects, independent of their anticoagulant activity. However, the cytoprotective effects require the administration at very high doses, leading to a bleeding tendency.The protein Z-dependent protease inhibitor (ZPI) belongs to the serpin superfamily, as AT, but in contrast to AT, inhibits only factors Xa (FXa) and XIa (FXIa) of coagulation. FXa inhibition by ZPI is potentiated by Protein Z (PZ), a vitamin K-dependent factor, which circulates in plasma in a complex with ZPI. In a whole blood model, I observed that ZPI exerts an inhibitory effect on lipopolysaccharide (LPS)-induced pro-inflammatory cytokines production (IL-6 and TNF-α). At high concentration (4 times physiological concentration), ZPI anti-inflammatory effect (AIE) is not modified by PZ or unfractionned heparin, which increase ZPI anticoagulant activity. Moreover, this AIE is still present using a reactive center loop variant of ZPI (ZPI Y387A), suggesting that the AIE of ZPI is independent of its anticoagulant activity. In vitro, in whole blood, ZPI induced an early increased of CCL-5, a chemokine with anti-inflammatory properties. These data are confirmed in vivo in a murine model of endotoxin shock where LPS is injected intraperitoneally. Simultaneously injection of recombinant human ZPI (rhZPI) with LPS led to lower plasma levels of IL-6 and TNF-α than in control mice, whereas higher CCL-5 levels were observed in peritoneal lavages.In addition, using purified proteins, we have shown that neutrophil elastase, an enzyme which decorates NETs, induces several cleavages of rhZPI. A quick and first cleavage is observed on the reactive centre loop of ZPI, inducing a loss of inhibitory activity towards FXa and FXIa. PZ does not protect ZPI from elastase degradation. ZPI proteolysis induced by NETs could contribute to their procoagulant activity.Lastly, in collaboration with the intensive care unit of Strasbourg Hospital, we studied plasma levels of PZ and ZPI in 100 patients with severe sepsis. During the first 24 hours, there was a significant decrease of plasma PZ levels, compared to levels of healthy subjects, whereas an approximately 2.5 times increase was observed for ZPI levels. These high levels of ZPI were still present at D3 and D7, whereas PZ levels regularly increased. Variations of PZ and ZPI levels were not predictive of the 30-day mortality rate, and not associated with DIC development.These results suggest that elevated concentrations of ZPI (4 times physiological concentration) could be an adjuvant therapy to septic shock, by decreasing pro-inflammatory cytokines production, but devoid of bleeding risk, since FXIa inhibition has antithrombotic activity without inducing haemorrhages.
62

The effect of farnesylated prelamin A accumulation on nuclear morphology and function

Goulbourne, Christopher Nicholas January 2011 (has links)
Failure to process prelamin A, by the enzyme ZMPSTE24, leads to the build up of farnesylated prelamin A, which has been implicated in causing the symptoms experienced in laminopathies and HIV therapy. A common feature to these conditions is the development of an irregular nuclear boundary, often including deep invaginations that form a nucleoplasmic reticulum. Additionally, dysregulated lipid synthesis is frequently associated with improper lamin A processing and I set out to address the molecular mechanisms behind these two features that could explain lipoatrophy experienced in patients. By using siRNA targeted against Zmpste24 I utilised an array of biochemical, molecular and imaging techniques to uncover a mechanism that leads to the production of a nucleoplasmic reticulum that was dependent on both the farnesylated tail of prelamin A and the phosphatidylcholine synthesising enzyme CCTα. The morphology of this structure consisted of an invagination of both the inner and outer nuclear membranes with a cytoplasmic core or just invagination of the inner nuclear membrane. Serial section dual axis electron tomography provided a new insight into the ultrastructural changes at the nuclear periphery that revealed novel structural features. The dysregulation of lipid synthesis was assessed by investigating the effects farnesylated prelamin A has on the distribution and dynamics of the transcription factor SREBP-1 and assessment of the downstream consequences this has on its targets that regulate adipocyte differentiation potential. Finally, the metabolomic profile of an HIV protease inhibitor that leads to prelamin A build up was generated and revealed increases in lipolysis, glycolysis and mediators of inflammation. The research presented offers a new insight into the development of a convoluted nuclear boundary and nucleoplasmic reticulum, in the context of lamin A mutants and how dysregulated lipid synthesis, caused by farnesylated prelamin A, leads to lipoatrophy.
63

Caractérisation de la SERPINA1, une antiprotéase différentiellement exprimée dans le cancer épithélial de l’ovaire

Normandin, Karine 12 1900 (has links)
Le cancer épithélial de l’ovaire est le cancer gynécologique le plus létal. La survie à 5 ans est de 30-40% chez les patientes atteintes d’une tumeur invasive (TOV), comparativement à 95% chez les patientes diagnostiquées pour une tumeur à faible potentiel de malignité ou borderline (LMP). Au laboratoire, l’analyse de l’expression des gènes de la micropuce à ADN U133 d’Affymetrix a révélé que la SERPINA1 est un gène dont l’expression varie entre les tumeurs LMP et TOV. La validation par Q-PCR nous a confirmé que cette antiprotéase est majoritairement surexprimée dans les tumeurs LMP, par rapport aux tumeurs bénignes (BOV) et aux tumeurs TOV. Nous avons donc surexprimé la SERPINA1 dans les lignées cellulaires invasives TOV 112D et TOV 1946 du cancer de l’ovaire et dérivé des clones stables. Les résultats obtenus nous indiquent que la surexpression de la SERPINA1 a un effet sur la capacité d’invasion et de migration cellulaire et non au niveau de la croissance cellulaire et la formation de structures tridimensionnelles. Les résultats issus de l’étude in vivo dans les souris SCID nous permettront de déterminer si la surexpression de la SERPINA1 a un effet sur la tumorigénèse ovarienne. Ainsi, la SERPINA1 demeure à notre avis un candidat d’intérêt pour tenter de mieux comprendre les différences biologiques entre les tumeurs LMP et TOV, ainsi que le rôle des protéases et de leurs inhibiteurs dans la progression tumorale du cancer de l’ovaire. / Epithelial ovarian cancer is the most lethal gynecologic cancer with a five-year survival rate of 30-40% in patients diagnosed with high-grade invasive disease (TOV). This is in stark contrast to the 95% five-year survival in patients diagnosed with low malignant potential (LMP) disease. It is therefore important to understand the biological differences between LMP and TOV. We have previously identified differential expression of SERPINA1 between serous LMP and TOV tumors through gene expression analysis using Affymetrix U133 DNA microarrays. Expression of this protease inhibitor in the majority of LMP tumors was confirmed and validated by Q-PCR. To study the effects of its overexpression on the invasive potential of ovarian cancer cell lines, SERPINA1 was cloned in the pcDNA3.1+ plasmid and stable clones were derived from two invasive ovarian cancer cell lines, TOV 112D and TOV 1946. Comparisons between clones and controls have shown no SERPINA1-dependent difference in cellular growth or spheroid formation. However, effects on cellular migration and invasion are observed in cells overexpressing SERPINA1. Results from an in vivo xenograft study in SCID mice will allow us to determine if SERPINA1 overexpression affects ovarian tumorigenesis. SERPINA1 remains an interesting candidate gene whose further characterization may lead to insights into its role, and the role of proteases and their inhibitors, in ovarian cancer disease progression.
64

Charakterisierung der immunmodulierenden Wirkung eines Cysteinproteasen-Inhibitors der humanpathogenen Filarie Onchocerca volvulus

Schönemeyer, Annett 12 December 2000 (has links)
Filarien persistieren bis zu 15 Jahren in ihren Wirten. Als eine Ursache dieser Persistenz diskutiert man die Fähigkeit der Filarien, die Immunantwort des Wirtes gezielt zu modulieren und eine zelluläre Hyporeaktivität zu induzieren. In der vorliegenden Arbeit wurde untersucht, ob ein sezernierter Cysteinproteasen-Inhibitor (Onchocystatin) der humanpathogenen Filarie Onchocerca volvulus immunmodulierende Eigenschaften besitzt und an der Herausbildung eines hyporeaktiven Immunstatus des Wirtes beteiligt ist. Für die Untersuchungen wurde Onchocystatin als full length Molekül (rOv17) und als verkürztes Molekül (trOv17) rekombinant hergestellt. Das verkürzte trOv17 besitzt aufgrund des Fehlens des N-terminalen Bereiches eine verminderte proteaseinhibitorische Aktivität. Die in vitro Studien mit den rekombinant hergestellten O. volvulus Cystatinen verdeutlichen, daß rOv17 und auch trOv17 potente Immunmodulatoren sind, die sowohl die antigenspezifische als auch die polyklonal-stimulierte Proliferation von humanen PBMC inhibieren. Die zelluläre Hyporeaktivität ist dabei auf die Modulation von Monozytenfunktionen zurückzuführen. rOv17 und trOv17 modulieren die Antigenpräsentation, die Zytokinproduktion und die Expression kostimulatorischer Signale von humanen Monozyten. So konnte gezeigt werden, daß rOv17 und trOv17 die Aktivität von humanem Cathepsin L und S inhibieren und die Expression von HLA-DR, CD40 und CD86 vermindern. Die Modulation der Zytokinproduktion durch rOv17 und trOv17 ist durch eine verstärkte TNF-alpha und IL-10 Produktion und durch eine verminderte IL-12 Produktion charakterisiert. Desweiteren konnte in Neutralisationsstudien mit anti-IL-10 Ak gezeigt werden, daß die verminderte Expression von HLA-DR, CD40 und CD86 Folge der durch rOv17 und trOv17 induzierten verstärkten IL-10 Produktion ist. Im Gegensatz dazu bleibt die verminderte IL-12 Produktion und die verminderte polyklonal-stimulierte Proliferation humaner PBMC auch nach der Neutralisation von IL-10 bestehen. Die Studien mit den rekombinant hergestellten O. volvulus Cystatinen zeigen, daß rOv17 und trOv17 ihr immunologisches Umfeld auf vielfältige Art und Weise modulieren. Dabei spielt vermutlich die Inhibition der Aktivität einer Wirtscysteinprotease, aber auch ein von der Funktion als Cysteinproteasen-Inhibitor unabhängiger Mechanismus eine Rolle. Der Cysteinproteasen-Inhibitor der Filarie O. volvulus besitzt somit die Eigenschaft, die Immunantwort des Wirtes zu modifizieren, und ist vermutlich eine wesentliche Komponente, die dem Parasiten eine lange Persistenz im Wirt ermöglicht. / Immune responses of individuals infected with filarial nematodes are characterized by a marked cellular hyporesponsiveness. The establishment of this hyporesponsiveness is considered as an important mechanism to avoid host immune responses which could eliminate the parasites. The present study is investigating the immunomodulatory potential of a 17 kD secreted cysteine protease inhibitor (onchocystatin) of the human pathogenic filaria Onchocerca volvulus. In vitro studies using recombinant onchocystatin (rOv17) identified this inhibitor as a potent immunomodulator. rOv17 suppresses the antigen-driven and the polyclonally-stimulated proliferation of human PBMC. This cellular hyporeactivity is due to the modulation of monocytic function by rOv17, comprising the modulation of antigenpresentation, the expression of costimulatory molecules and the production of cytokines. Thus rOv17 strongly inhibits the activity of human cathepsin L and S and reduces the expression of MHC class II molecules as well as the expression of CD40 and CD86 on human monocytes. The modulation of cytokine production by rOv17 is characterized by an initial increase of TNF-alpha which is followed by an increase of IL-10 and a decrease of IL-12. By neutralization studies it was shown that the suppression of MHC class II molecules and of CD86 and CD40 is mediated by the rOv17 induced increase of IL-10. In contrast cellular hyporeactivity and the reduced IL-12 production remain unaffected by neutralization of IL-10. In comparison to rOv17 a truncated onchocystatin (trOv17) with lowered protease inhibitory activity was investigated. Surprisingly even trOv17 is immunomodulatory active suggesting that immunomodulation by onchocystatin is mediated by both an inhibitor-dependent and an inhibitor-independent mechanism. These data demonstrate that onchocystatin is a potent immunomodulator of host immune responses and in consequence is an essential component that enables the parasites a long persistence within their hosts.
65

Characterisation of Proteins from Grevillea robusta and NMR Studies of the Serine Protease Inhibitor

Kruger, Sarah Jane, n/a January 2004 (has links)
Proteins that recognise the sugar surface structures on cells have an enormous potential to be used as tools in the characterisation of these structures. A group of proteins, called lectins, have been identified that can bind to carbohydrate complexes on the receptors of cells. The crude extract from Grevillea robusta seeds was found to contain lectin-like proteins that were different from most other lectins, as they would specifically target the receptors of white blood cells and not those found on red blood cells. Therefore, the lectin isolated from G.robusta could be used as a tool to identify the specific surface structures on white blood cells. The lectin was isolated using affinity chromatography where a complex (oligosaccharide) matrix was used. Agglutination, binding and sugar inhibition assays confirmed the isolated protein was a lectin. The lectin was found in low amounts (up to 5% of the total protein content) within the seeds of G.robusta. As a result of this low yield, the identification of the lectin by PAGE was difficult because the levels of protein were beyond the detection limit of the commercial staining reagents. The lectin was called the GR2 protein and was characterised as a monocot mannose binding lectin based on its sugar specificity for only mannose. A serine protease inhibitor was isolated from the seeds of G.robusta using two different chromatography methods, reverse phase HPLC (GR1.HPLC) and gel filtration chromatography (GR1.GF). Ion exchange chromatography was used to initially separate the proteins in the crude extract and the fraction containing the GR1 protein was further purified using reverse phase HPLC (GR1.HPLC). N-terminal sequencing results of the GR1.HPLC protein, showed evidence of proteolytic cleavage during the extraction process, which lead to the second purification method being established. Protease inhibitors were added to the buffers prior to being purified by gel filtration chromatography, which resulted in the GR1 protein being isolated from the crude extract without the presence of the contaminating protein. Mass spectroscopy identified the molecular weight of the GR1 protein to be 6669Da and the full amino acid sequence was derived by cDNA techniques. Sequence alignment studies of the GR1 protein showed significant similarities with the Bowman-Birk inhibitor. The positioning of the cysteine residues were conserved throughout the Bowman-Birk superfamily, however these residues were not conserved within the GR1 protein. Competitive inhibition assays on the GR1 protein revealed the protein could inhibit both trypsin and chymotrypsin at similar levels to that seen for the Bowman-Birk inhibitor. Therefore, the GR1 protein was characterised as a member of the Bowman-Birk superfamily of serine protease inhibitors. The three-dimensional structure of the GR1 protein was determined using two-dimensional NMR spectroscopy. Computer programs such as XEASY, DYANA and SYBYL® were used to tabulate the information taken from the 2D experiments, generate structures and minimise these structures respectively. The solution structure of the GR1 protein was found to contain a region of antiparallel β-sheet structure that corresponded to the trypsin binding site and the remainder of the protein consisted of loops and turns that were held together by disulfide bridges (the chymotrypsin-binding region). Structural similarities between the GR1 protein and the Bowman-Birk inhibitor existed only in the trypsin-binding site of the Bowman-Birk inhibitor. The GR1 protein is the first member of the Proteaceae family to be characterised as a Bowman-Birk inhibitor. This thesis outlines the isolation and biochemical characterisation of the two proteins found within Grevillea robusta and also describes the steps involved and results obtained in determining the three-dimensional structure of the GR1 protein.
66

家蚕の代謝特性とその有効利用

山下, 興亜, 古賀, 克己, 江口, 正治, 佐々木, 卓治, 柳沼, 利信, 小林, 迪弘, 森島, 伊佐夫, 大西, 英爾, 小山内, 実 03 1900 (has links)
科学研究費補助金 研究種目:総合研究(A) 課題番号:60304024 研究代表者:山下 興亜 研究期間:1985-1987年度
67

ヒト糸球体メサンギウム細胞特異的遺伝子のクロ-ニング

宮田, 敏男 03 1900 (has links)
科学研究費補助金 研究種目:一般研究(B)(2) 課題番号:07457240 研究代表者:宮田 敏男 研究期間:1995-1996年度
68

Caractérisation de la SERPINA1, une antiprotéase différentiellement exprimée dans le cancer épithélial de l’ovaire

Normandin, Karine 12 1900 (has links)
Le cancer épithélial de l’ovaire est le cancer gynécologique le plus létal. La survie à 5 ans est de 30-40% chez les patientes atteintes d’une tumeur invasive (TOV), comparativement à 95% chez les patientes diagnostiquées pour une tumeur à faible potentiel de malignité ou borderline (LMP). Au laboratoire, l’analyse de l’expression des gènes de la micropuce à ADN U133 d’Affymetrix a révélé que la SERPINA1 est un gène dont l’expression varie entre les tumeurs LMP et TOV. La validation par Q-PCR nous a confirmé que cette antiprotéase est majoritairement surexprimée dans les tumeurs LMP, par rapport aux tumeurs bénignes (BOV) et aux tumeurs TOV. Nous avons donc surexprimé la SERPINA1 dans les lignées cellulaires invasives TOV 112D et TOV 1946 du cancer de l’ovaire et dérivé des clones stables. Les résultats obtenus nous indiquent que la surexpression de la SERPINA1 a un effet sur la capacité d’invasion et de migration cellulaire et non au niveau de la croissance cellulaire et la formation de structures tridimensionnelles. Les résultats issus de l’étude in vivo dans les souris SCID nous permettront de déterminer si la surexpression de la SERPINA1 a un effet sur la tumorigénèse ovarienne. Ainsi, la SERPINA1 demeure à notre avis un candidat d’intérêt pour tenter de mieux comprendre les différences biologiques entre les tumeurs LMP et TOV, ainsi que le rôle des protéases et de leurs inhibiteurs dans la progression tumorale du cancer de l’ovaire. / Epithelial ovarian cancer is the most lethal gynecologic cancer with a five-year survival rate of 30-40% in patients diagnosed with high-grade invasive disease (TOV). This is in stark contrast to the 95% five-year survival in patients diagnosed with low malignant potential (LMP) disease. It is therefore important to understand the biological differences between LMP and TOV. We have previously identified differential expression of SERPINA1 between serous LMP and TOV tumors through gene expression analysis using Affymetrix U133 DNA microarrays. Expression of this protease inhibitor in the majority of LMP tumors was confirmed and validated by Q-PCR. To study the effects of its overexpression on the invasive potential of ovarian cancer cell lines, SERPINA1 was cloned in the pcDNA3.1+ plasmid and stable clones were derived from two invasive ovarian cancer cell lines, TOV 112D and TOV 1946. Comparisons between clones and controls have shown no SERPINA1-dependent difference in cellular growth or spheroid formation. However, effects on cellular migration and invasion are observed in cells overexpressing SERPINA1. Results from an in vivo xenograft study in SCID mice will allow us to determine if SERPINA1 overexpression affects ovarian tumorigenesis. SERPINA1 remains an interesting candidate gene whose further characterization may lead to insights into its role, and the role of proteases and their inhibitors, in ovarian cancer disease progression.
69

Comparación de la respuesta virológica según los esquemas terapéuticos prescritos a pacientes con VIH que presentaron la mutación M184V en dos hospitales nacionales durante los años 2008 al 2019

Paredes Pacheco, Raisa Alessandra, Véliz Julca, Fritner 09 April 2019 (has links)
Introducción: En pacientes con VIH en TARV y fallo virológico a primera línea, establecer un esquema terapéutico tras haber identificado la mutación M184V, que confiere resistencia, representa una disyuntiva. Objetivo: Comparar la respuesta virológica de los esquemas terapéuticos prescritos a pacientes con VIH que presentaron la mutación M184V en dos hospitales nacionales de Lima, Perú durante los años 2008 a 2019 y determinar los factores de riesgo asociados a una mala respuesta virológica. Métodos: Se desarrolló un estudio de cohorte retrospectivo. Resultados: Un total de 175 participantes fueron elegibles para el estudio. El sexo masculino predominó (75.4%), la mediana de edad actual fue 41 años (IQR 35.84 ; 47.47) y tiempo en TARV fue 89 meses (IQR 57.7 ; 124.53). La mediana de carga viral inicial fue 4.5 log10 (IQR 3.97 ; 5.09) y el tiempo entre la genotipificación y el cambio de terapia fue 2 meses (IQR 0 ; 3.57). El esquema antirretroviral más utilizado fue IP + 2 INTR (55.4%). Con el esquema IP + INI se obtuvo 69% menos riesgo de mala respuesta virológica [p=0.019 (IC 95% 0.117 ; 0.825)]. Conclusiones: En los pacientes con VIH y mutación M184V, el esquema IP + INI ha demostrado una mayor disminución de la carga viral de control y, así, una buena respuesta virológica. Los factores de riesgo asociados a una mala respuesta virológica fueron la demora entre la genotipificación y el cambio de terapia, niveles elevados de carga viral inicial y mala adherencia. / Introduction: In patients with HIV in ART and virological failure to the first-line regimen, establishing a therapeutic regimen after having identified the M184V mutation, which confers ART resistance, represents a dilemma. Objective: To compare the virological response of the therapeutic regimens prescribed to patients with HIV who presented the M184V mutation in two national hospitals in Lima, Peru during the years 2008 to 2019, and to determine the risk factors associated with poor virological response. Methods: A retrospective cohort study was developed based on the information of the HIV program participants with the M184V mutation. Results: A total of 175 participants were eligible for the study. The male sex predominated (75.4%), the current median age was 41 years (IQR 35.84, 47.47) and the time on ART was 89 months (IQR 57.7, 124.53). The median initial viral load was 4.5 log10 copies/ml (IQR 3.97, 5.09) and the time between genotyping and the change of therapy was 2 months (IQR 0; 3.57). The most used antiretroviral regimen was PI + 2 NRTIs (55.4%). With the PI + INI ART, 69% less risk of poor virological response was obtained [p=0.019 (CI 95% 0.117 ; 0.825)]. Conclusions: In patients with HIV and the M184V mutation, the PI + INI ART has shown a greater decrease in control viral load and, thus, a good virological response. The risk factors associated with a poor virological response were the delay between genotyping and change of therapy, high levels of initial viral load, and poor adherence among the participants. / Tesis
70

Rôle des serpines, inhibiteurs de protéases à serine, du microbiote digestif humain dans les maladies inflammatoires de l'intestin / Involvement of the serpins, serine-protease inhibitors, from the human gut microbiota in inflammatory bowel diseases

Mkaouar, Héla 25 June 2019 (has links)
Les inhibiteurs des protéases à sérine (Serpins) constituent une classe d'enzymes très peu étudiée chez les bactéries. Dans ce travail de thèse nous nous sommes intéressés à l'étude des serpins provenant du microbiote intestinal et l'investigation de leur potentiel anti-inflammatoire pour le traitement des maladies inflammatoires chroniques de l'intestin (MICI) chez l'homme. Pour cela nous avons identifié les serpins provenant du microbiote intestinal humain et analysé leur diversité ainsi que leur distribution entre les individus malades et sains. Ces données nous ont permis d'isoler les serpins significativement associées aux MICI. La purification de quarte d'entre elles nous a amené à démontrer qu'elles inhibent les protéases humaines impliquées dans les MICI. L'analyse biochimique et cinétique approfondie de ces protéines a montré qu'elles possèdent des propriétés originales notamment leur efficacité d'inhibition élevée. L'étude de l'effet protecteur de trois serpins chez un modèle animal de colite a démontré pour la première fois l'efficacité des serpins in vivo démontrant ainsi leur potentiel thérapeutique. / Serine protease inhibitors (Serpins) are a class of proteins that reamin poorly studied in bacteria. In this thesis we are interested in the study of serpins originating from the intestinal microbiota and the investigation of their anti-inflammatory potential for the treatment of inflammatory bowel diseases (IBD) in humans. For this we have identified serpins from the human gut microbiota and analyzed their diversity as well as their distribution between healthy and IBD patients. These data allowed isolating serpins significantly associated with IBD. The purification of four of them led us to demonstrate that they inhibit human proteases involved in IBD. Biochemical and kinetic analysis of these proteins showed that they exhibit original properties, in particular their high inhibition efficiency. The study of the protective effect of three serpins in an animal model of colitis demonstrated for the first time the efficacy of serpins in vivo demonstrating thus their therapeutic potential.

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