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Bidouba-Sanvany, Doll-Spencerh. "Simulation de l'interaction thermo-acousto-fluidique en puits : application à la stimulation cellulaire". Electronic Thesis or Diss., Université de Lorraine, 2023. http://www.theses.fr/2023LORR0279.
Pełny tekst źródłaSurface acoustic waves (SAW) are currently being used to study their interaction with biological particles to perform studies of cell proliferation, growth, death and migration. The effect of shear stress on cells has been shown to play an important role in cell modification, providing further details on their function and potential changes. Stamp et al. present an ultrasound approach to dynamic stimulation and tissue healing of SaOs-2 osteoblastic cells using surface acoustic waves (SAW) on a chip. These studies are performed without unwanted side effects such as increased substrate temperature or nutrient flux associated with SAW. These results demonstrate that the dynamic mechanical and electrical stimulation induced by surface acoustic waves directly promotes cell growth and thus rapid tissue regeneration. S. Brugger presents studies on in vitro wound healing and cell growth under the influence of radiofrequency (rf) cell stimuli. These stimuli are generated either by piezoactive surface acoustic waves (SAW) or by electric fields generated by microelectrodes. His results show that vibratory stimulation of cells based on surface acoustic waves can be an alternative to conventional ultrasound treatment. Shear stresses acting on the cells are responsible for the various changes observed after acoustic wave stimulation, but it is impossible to determine these stresses experimentally, so a simulation approach is necessary. The goal of this thesis is to develop a simulation that will allow us to understand the phenomenon of Rayleigh/liquid interaction in a microchannel or droplet and to quantify the stresses exerted on biological particles during surface acoustic wave stimulation, as well as to carry out an optimization study. The study investigated the effects of different frequencies on blood cells (circulating) and bone cells (adherent) using a vertical probe immersed in a well with a frequency of 20 MHz and 40 MHz, respectively. Additionally, the research took into consideration the liquid heating
GUFFLET, ESCHWEGE VALERIE. "Les anticorps antiphospholipides : lien physiopathologique entre la stimulation cellulaire et les reponses procoagulantes et immunitaires". Université Louis Pasteur (Strasbourg) (1971-2008), 1998. http://www.theses.fr/1998STR13064.
Pełny tekst źródłaBernard, Isabelle. "Phénomènes d'activation cellulaire et plasmatique de l'hémostase lors des traitements de stimulation pour fécondation in vitro". Montpellier 1, 1994. http://www.theses.fr/1994MON11125.
Pełny tekst źródłaXia, Rong. "Étude des effets de la stimulation électrique à haute fréquence dans un modèle cellulaire in vitro". Université Joseph Fourier (Grenoble), 2005. https://tel.archives-ouvertes.fr/tel-00009865.
Pełny tekst źródłaA system for electrical stimulation on cells lines in vitro was optimized for studying cellular and molecular mechanism of high frequency electrical stimulation. Two cells lines (GH3 and PC12) were analysed at the transcriptomic and proteomic level as well as for the impact on hormonal secretion and neurotransmitter release. We compared PRL secretion of GH3 cell by HFS, LFS and dopamine as well as catecolamine (DA, AD and NA) secretion of PC12 cell treated by HFS, LFS and 6-OHDA. Proteomic synthesis of stimulated cells were analysed by 35S methionine incorporation and by SELDI-TOF-MS. At last we have investigated modifications of gene expression of stimulated cells using DNA nylon microarray based on long oligonucleotides and radioactive detection. First experiment demonstrated that HFS induced a significant decrease of the amount of prolactin to a level comparable to the level obtained with dopamine, one well known inhibitor of prolactin. Similarly, the amount of catecholamines detected in the cell culture medium was significantly down regulated. Transcriptomic data manifested the existence of characteristic expression profiles for high frequency electrical stimulation. About 100 discriminatory genes were individualized upon HFS involved in the proteomic synthesis, calcium signalisation and cellular energetic. We confirmed the impact of HFS on protein synthesis with SELDI-TOF technique and methionine incorporation. One original HFS mechanism has been validated, involving protein synthesis neutralisation in the reacted inactivation of neuronal structures. Implication of calcium signalisation and PKC pathway were also suggested
Carras, Sylvain. "Rôles de la stimulation chronique du TCR et de la reprogrammation cellulaire dans les lymphomes T périphériques". Thesis, Lyon, 2018. http://www.theses.fr/2018LYSE1322/document.
Pełny tekst źródłaPeripheral T-cell lymphomas (PTCL) are rare non Hodgkin malignant lymphomas emerging from mature T or NK cells. PTCL are highly heterogeneous and mainly misunderstood. As several evidences pointed the potential role of TCR chronic stimulation in human T-cell lymphomagenesis, we developed a murine model based on chronic TCR stimulation to address this question. In this model, transfer of p53-/- T-cells into T-cell deficient mice (CD3e-/-) triggered PTCL development in 60% of cases with a median survival of 230 days while transfer of wt T-cells in CD3e-/- mice did not lead to PTCL development. These PTCL exhibited an effector-memory phenotype CD62LLo-CD44hi-CD122lo-CD25lo associated with a dramatic downregulation of TCR pathway genes expression consistent with a chronic TCR stimulation highlighting it’s implication in lymphomagenesis. The analysis of these PTCL revealed that a large majority of cases (80%) do not depend anymore on TCR stimulation for their growth and survival and that they acquire innate-like features with expression of inhibitory NKR (NKiR) and activating NK receptors (NKaR) as well as the adaptor proteins DAP12 or FceRIg. Expression of these receptors is associated with the expression of SYK and PLC?2, which are classical key effectors downstream of NKaR. We show that these NKaR are functional and can mediate TCR-independent activation in mPTCL and that this signaling is involved in cell survival/proliferation as in vivo blockade of NKG2D and NKp46 delays PTCL development in PTCL transplantation experiments. In parallel, we studied NKR, Syk and PLCg2 expression in human PTCL and found that some entities express a large range of these receptors as well as Syk and PLCg2, suggesting similar lymphomagenesis mechanisms in some human PTCL
Gustave-Dit-Duflo, Sylvie. "Adaptation et restauration des fonctions vestibulaires : Analyses comportementale et cellulaire après lésion ou stimulation vestibulaire chez l'animal". Montpellier 2, 1998. http://www.theses.fr/1998MON20128.
Pełny tekst źródłaDehez, Stéphanie. "Stimulation des voies JNK et P38MAPK par les peptides gastriniques : mécanismes d'activation et rôle dans la prolifération cellulaire". Toulouse 3, 2001. http://www.theses.fr/2001TOU30093.
Pełny tekst źródłaZanin, Carole. "Ecotaxie des cellules de la lignée B spécifiques d'antigènes microbiens après stimulation par voie orale". Nancy 1, 1994. http://www.theses.fr/1994NAN10010.
Pełny tekst źródłaParaskevopoulos, Yannis. "Utilisation des enveloppes cellulaires de levure pour la stimulation de la fermentation malolactique : interprétation de leur mode d'action". Bordeaux 2, 1988. http://www.theses.fr/1988BOR20029.
Pełny tekst źródłaDing, Can. "The influence of Notch over-stimulation on muscle stem cell quiescence versus proliferation, and on muscle regeneration". Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066399/document.
Pełny tekst źródłaMuscle stem cell transplantation possesses great potential for long-term repair of dys-trophic muscle. However expansion of muscle stem cells ex vivo significantly reduces their engraftment efficiency since the myogenic potential is dramatically lost in culture. The Notch signaling pathway has emerged as a major regulator of muscle stem cells (MuSCs) and it has recently been discovered that high Notch activity is crucial for maintaining stemness in MuSCs. This feature might be exploited and developed into a novel therapeutic approach.Murine MuSCs were freshly isolated and seeded on culture vessels coated with Dll1-Fc, which fused Delta-like-1 extracellular domain with human Fc, to activate Notch sig-naling and with human IgG as a control. The rAAV gene delivery system was em-ployed to express Dll1 in murine muscles. P3 mice were treated with AAV for 3 weeks and 6 weeks to investigate the effect of Dll1 during postnatal development. To investi-gate the regeneration process, AAV were injected into mdx muscles whereas wild-type mice were used as control.Higher potential stemness (marked by Pax7 positivity) was observed in MuSCs grow-ing on a Dll1-Fc surface as compared to their counterparts on the control surface, while their proliferation rate was reduced. During postnatal development, overstimulation of Notch signaling by Dll1 on the mus-cle fibers was able to enlarge the Pax7+ cell pool, while also resulting in decreased muscle mass and smaller muscle fibers without affecting the accretion of myonuclei into the fiber. In quiescent (wild-type) MuSCs, overstimulation of Notch signaling did not have any discernible effect. Overexpression of Dll1 in mdx muscle decreased the muscle mass and enlarged the muscle stem cell pool, while muscle regeneration re-mained unaffected. By investigating Notch stimulation in MuSCs both in vitro and in vivo, we demonstrate that high Notch activity preserves stemness via inhibition of MuSCs proliferation and myogenic differentiation. Our findings point out that the Dll1 molecule, as a canonical Notch ligand, might have a therapeutic potential in cell-based therapies against muscu-lar dystrophies
Bardoul, Michèle. "Récepteurs AMPA et kai͏̈nate précoces dans le tronc cérébral embryonnaire : effets de leur blocage ou de leur stimulation "in vitro"". Montpellier 2, 1997. http://www.theses.fr/1997MON20177.
Pełny tekst źródłaDing, Can. "The influence of Notch over-stimulation on muscle stem cell quiescence versus proliferation, and on muscle regeneration". Electronic Thesis or Diss., Paris 6, 2015. http://www.theses.fr/2015PA066399.
Pełny tekst źródłaMuscle stem cell transplantation possesses great potential for long-term repair of dys-trophic muscle. However expansion of muscle stem cells ex vivo significantly reduces their engraftment efficiency since the myogenic potential is dramatically lost in culture. The Notch signaling pathway has emerged as a major regulator of muscle stem cells (MuSCs) and it has recently been discovered that high Notch activity is crucial for maintaining stemness in MuSCs. This feature might be exploited and developed into a novel therapeutic approach.Murine MuSCs were freshly isolated and seeded on culture vessels coated with Dll1-Fc, which fused Delta-like-1 extracellular domain with human Fc, to activate Notch sig-naling and with human IgG as a control. The rAAV gene delivery system was em-ployed to express Dll1 in murine muscles. P3 mice were treated with AAV for 3 weeks and 6 weeks to investigate the effect of Dll1 during postnatal development. To investi-gate the regeneration process, AAV were injected into mdx muscles whereas wild-type mice were used as control.Higher potential stemness (marked by Pax7 positivity) was observed in MuSCs grow-ing on a Dll1-Fc surface as compared to their counterparts on the control surface, while their proliferation rate was reduced. During postnatal development, overstimulation of Notch signaling by Dll1 on the mus-cle fibers was able to enlarge the Pax7+ cell pool, while also resulting in decreased muscle mass and smaller muscle fibers without affecting the accretion of myonuclei into the fiber. In quiescent (wild-type) MuSCs, overstimulation of Notch signaling did not have any discernible effect. Overexpression of Dll1 in mdx muscle decreased the muscle mass and enlarged the muscle stem cell pool, while muscle regeneration re-mained unaffected. By investigating Notch stimulation in MuSCs both in vitro and in vivo, we demonstrate that high Notch activity preserves stemness via inhibition of MuSCs proliferation and myogenic differentiation. Our findings point out that the Dll1 molecule, as a canonical Notch ligand, might have a therapeutic potential in cell-based therapies against muscu-lar dystrophies
Qian, Chengrui. "Etude des intéractions entre les étapes précoces des voies de signalisation dépendantes du TCR et de CD28 dans l'initiation de l'activation des lymphocytes T naïfs". Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM4058.
Pełny tekst źródłaT cell activation is initiated by signaling pathways triggered upon ligand engagement of the TCR and co-stimulatory receptors, respectively, with CD28 being the major one among the latter class of molecules on naïve T cells. At the same time, such activation needs to be tightly regulated, since its improper occurrence might be of detrimental consequences. We report here that interactions between TCR and CD28 early signaling pathways generate coincidence detection mechanism in the initiation of naïve T cell activation. First, we found that in naïve CD4+ T cells, TCR engagement with pMHC cognate ligand or antibody significantly increases the 2D binding of CD28 to its B7 ligands and this increase depends on both the cytoplasmic tail of CD28 and activity of src kinases. Moreover, TCR-pMHC interaction was observed to enhance the tyrosine phosphorylation of CD28 induced upon B7 engagement. Analysis of the receptor-triggered signaling events in naïve CD4+ T cells showed that alone TCR or CD28 stimulation was only capable of inducing a weak or minimal Ca2+ response in spite of the readily detected phospholipase C-1 phosphorylation, but the concurrent stimulation of both pathways efficiently elicited strong and sustained Ca2+ mobilization involving the CRAC channels. Our study has thus uncovered occurrence of the coincidence detection at two major steps during the TCR- and CD28-triggered activation of naïve T cells, namely the ligand binding and triggering of the receptors and the intracellular mobilization, which provides important new insights into the mechanism of primary immune response initiation as well as its regulation
Hamza-Talha, Saliha. "Stimulation rapide du renouvellement de l'atp par des facteurs de croissance dans des fibroblastes de souris swiss : relation avec d'autres evenements precoces". Paris 6, 1987. http://www.theses.fr/1987PA066423.
Pełny tekst źródłaLemasson, Morgane. "Etude de la neurogenèse des interneurones bulbaires : rôle de l'expérience olfactive précoce". Paris 6, 2005. http://www.theses.fr/2005PA066151.
Pełny tekst źródłaBensaid, Samir. "Mise en place de contre-mesures pour limiter la perte protéique de cellules musculaires squelettiques consécutive à l’hypoxie cellulaire". Thesis, Lille 2, 2019. http://www.theses.fr/2019LIL2S021.
Pełny tekst źródłaBackground and aims : Chronic exposure to severe hypoxia has deleterious effects on the muscular system, in particular on skeletal muscle mass. Hypoxia leads to imbalance of protein homeostasis, decreasing protein synthesis (mainly regulated through PI3K-Akt-mTOR pathway) while increasing protein degradation (mainly through autophagy and proteasomal degradation). In contrast, mechanical stimuli and nutrients, particularly the branched-chain amino acids (BCAA), induce activation of the mTOR pathway in human and rat skeletal muscle as well as and in cultured muscle cells, and decrease protein catabolism. In a model of skeletal muscle cell culture, we attempt to determine whether the combination of mechanical stimulation, nutritional supplementation and reoxygenation could reverse the deleterious effects of hypoxia on protein homeostasis.Experimental methodsWe induced a hypoxic stress on skeletal muscle murine cells differentiated into myotubes C2C12: four days after differentiation, the C2C12 myotubes were placed into a hypoxic chamber at 4% O2 for 24h. Electrical stimulation was applied to the cells using a pulse generator to provide electric pulses. Following the ES treatment, myotubes were firstly supplemented with branched-chain amino acids (BCAA: mixture of leucine, isoleucine and valine added to culture media) while placed to normoxia during 2 hours (corresponding so to a reoxygenation protocol).ResultsAfter 24 hours of hypoxia, the morphological analysis of myotubes shows a significant decrease in their diameter, translating the activation of protein degradation pathways at the expense of protein synthesis pathways. When applied separately, each treatment has little effect on the mTOR pathway and morphology of myotubes. However, the combination of electrical stimulation, supplementation BCAA and reoxygenation lead to an increase of the phosphorylation of key proteins involved in protein synthesis pathway (Akt and p70S6 kinase), thus reflecting their activation state. In addition, morphological analysis shows a significant increase in myotube diameter and fusion index (reflecting the state of differentiation), a sign of the presence of muscle hypertrophy.ConclusionOur preliminary results suggested that mTOR pathway responds to a combination of electrostimulation, nutrient supplementation and reoxygenation by phosphorylation of key regulators of protein synthesis, and could reverse the protein loss induced by hypoxia
Rose, Mélanie. "MACBETH : MACrophages BoostEd THerapy : Stratégie de réactivation des macrophages au sein de la tumeur via l’inhibition de proproteines convertases et la stimulation de TLRs". Thesis, Lille 1, 2020. http://www.theses.fr/2020LIL1S102.
Pełny tekst źródłaIn brain tumors such as gliomas, infiltrating macrophages are abundant and associated with a poor prognosis. Their functional plasticity is essential for tumor development. They exhibit anti-inflammatory and pro-tumoral phenotype promoting tumor growth and immunosuppression. Moreover, they impact the efficacy of chemotherapy and may lead to drug resistance. Therefore, this project aims to reorient macrophages towards a pro-inflammatory and anti-tumoral phenotype. For this purpose, the proprotein convertase 1/3 (PC1/3) has been targeted since it plays a key role to skew their phenotype. Indeed, we showed that macrophages released spontaneously pro-inflammatory factors after PC1/3 inhibition. Besides, PC1/3 inhibition combined with TLR4 activation with Paclitaxel induced the secretion of anti-tumoral factors effective against a glioma cell line. To go further, we also inhibited various proprotein convertases with a commercial inhibitor. We found that such treatment reduced the viability and the invasion of glioma cells in co-culture with macrophages. In addition to its direct anti-tumoral activity, it decreased the immunosuppressive capacity of cancer cells as well as the pro-tumoral functions of macrophages. Finally, we also demonstrated that stimulation of TLR3 with Poly (I:C) sustained the activity of the proprotein convertases inhibitor. Therefore, proprotein convertases inhibition associated with TLR activation is a promising strategy to reactivate tumor-associated macrophages and develop a potent anti-glioma therapy
Gironcel, Daisy. "Stimulation d'une phospholipase C et d'une phosphoinositide 3-kinase lors de l'adhésion cellulaire via l'intégrine alphaIIbbêta3. Mise en évidence d'une 3-phosphatase spécifique des 3-inositol lipides mono- et bisphosphate". Toulouse 3, 1996. http://www.theses.fr/1996TOU30149.
Pełny tekst źródłaXu, Binbin. "Étude de la Dynamique des Ondes Spirales à l'Échelle Cellulaire par Modèles Expérimental et Numérique". Phd thesis, Université de Bourgogne, 2012. http://tel.archives-ouvertes.fr/tel-00955873.
Pełny tekst źródłaDumas, Virginie. "Réponse des ostéoblastes à des stimulations physiques basées sur des contraintes mécaniques basses amplitudes hautes fréquences. Implication en ingénierie tissulaire". Phd thesis, Université Jean Monnet - Saint-Etienne, 2010. http://tel.archives-ouvertes.fr/tel-00670904.
Pełny tekst źródłaCantereau, Anne. "Étude, par imagerie confocale de fluorescence, de la dynamique spatio-temporelle du Ca2+ libre intracellulaire et de son évolution au cours de la différenciation des cellules musculaires squelettiques de rat in vitro". Bordeaux 2, 1997. http://www.theses.fr/1997BOR28493.
Pełny tekst źródłaSchwartz, Christine. "Muscle LIM protein and Nesprin-1 in Mechanotransduction". Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066374/document.
Pełny tekst źródłaI studied three striated muscle proteins that are participating in two different pathways of mechanotransduction, which is the translation of a physical stimulus into a biochemical signal.When isolated cardiomyocytes are stretched in 2D, MLP shuttles to the nucleus. Without shuttling MLP, these cells fail to respond to the stretch stimulus. Human patients with MLP-mutations develop cardiomyopathies, as well as mice with a knock-out of MLP (MLP-/-). By expressing mutated MLP in neonatal cardiomyocytes of MLP-/- mice, I wanted to elucidate the role of mutant MLP. Surprisingly, MLP did shuttle after stretching of 2D but not 3D cell cultures. Although I could not solve this issue, I prepared the setup for subsequent experiments.Nesprins are part of the nuclear envelope (NE) spanning LINC complex, which connects the cytoskeleton with the nucleus. Myoblasts from patients with mutations in Nesprins or LINC-associated Lamins displayed deformed nuclei and had defects in mechanosensitive responses with an elevated level of stress fibers and focal adhesions on soft surfaces. This phenotype could be rescued by knock-down of formin FHOD1, a downstream target of ROCK and SRC, which also were highly active in the mutant cells. While mutations in Nesprins and Lamins are thought to lead to mechanical instability of the NE, these results indicate that signaling pathways through the NE are disturbed as well
Habes, Chahrazed. "Stimulation du signal calcique et de la migration des cellules cancéreuses mammaires par le peptide LL-37 : un mécanisme d’attachement membranaire impliquant les glycosaminoglycanes et les syndécanes". Thesis, Tours, 2019. http://www.theses.fr/2019TOUR3807.
Pełny tekst źródłaInitially characterized by its antimicrobial activities, LL-37 has also been shown to significantly contribute to tumor development. On breast cancer cell lines, LL-37 increases intracellular calcium and their migration via the activation of PI3K/AKT signaling. Its all-D enantiomer (D)-LL-37 induces similar effects, which excludes an protein-protein interaction of LL-37 in a classic ligand-receptor manner. Its structure of an amphipathic a-helix with a net charge of +6 gave rise to the hypothesis that the peptide uses the negative charges of sulfoglycans or sialic acids to facilitate its attachment to the cell membrane and to induce its activities. Whereas several lectins, specifically attaching to sialylated or sulfated structures, blocked the activities of LL-37 on both calcium increase and cell migration, the suppression of several sialyltransferases had no effect. However, the competitive use of glycoaminoglycans (GAG) and chrondroitin and sulfated heparin, or treatment of the cell surface with chondroitinase and heparinase resulted in an activity loss of 50-100%. Similar results were obtained by confirmed by blocking the synthesis of GAGs with Methylumbelliferyl β-D-xyloside, and by suppression of glycan sulfurylation by sodium chlorate. Using a candidate approach by suppressing proteoglycan synthesis by RNA interference, syndecan 4 was shown to be involved in the activities of LL-37. This leads to the conclusion that sulfated GAGs linked to syndecans 4 guides the association of LL-37 to the membrane of cancer cells, thus being a mediator of its activities
Schwartz, Christine. "Muscle LIM protein and Nesprin-1 in Mechanotransduction". Electronic Thesis or Diss., Paris 6, 2016. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2016PA066374.pdf.
Pełny tekst źródłaI studied three striated muscle proteins that are participating in two different pathways of mechanotransduction, which is the translation of a physical stimulus into a biochemical signal.When isolated cardiomyocytes are stretched in 2D, MLP shuttles to the nucleus. Without shuttling MLP, these cells fail to respond to the stretch stimulus. Human patients with MLP-mutations develop cardiomyopathies, as well as mice with a knock-out of MLP (MLP-/-). By expressing mutated MLP in neonatal cardiomyocytes of MLP-/- mice, I wanted to elucidate the role of mutant MLP. Surprisingly, MLP did shuttle after stretching of 2D but not 3D cell cultures. Although I could not solve this issue, I prepared the setup for subsequent experiments.Nesprins are part of the nuclear envelope (NE) spanning LINC complex, which connects the cytoskeleton with the nucleus. Myoblasts from patients with mutations in Nesprins or LINC-associated Lamins displayed deformed nuclei and had defects in mechanosensitive responses with an elevated level of stress fibers and focal adhesions on soft surfaces. This phenotype could be rescued by knock-down of formin FHOD1, a downstream target of ROCK and SRC, which also were highly active in the mutant cells. While mutations in Nesprins and Lamins are thought to lead to mechanical instability of the NE, these results indicate that signaling pathways through the NE are disturbed as well
Sukkar, Dani. "Role of Nosema cerenae and pesticides on the decline of bees : Studies using a multifactorial approach : “Tipping the scale of honeybee immune responses - The effect of pesticides on immune-stimulation mimicking Nosema spp.”". Electronic Thesis or Diss., Université de Lorraine, 2023. http://www.theses.fr/2023LORR0086.
Pełny tekst źródłaHoneybee are facing the global threat of colony collapse disorder (CCD) leading colony deaths and decline in their numbers affecting their environmental and agronomic contribution in pollination of plants and commercial crops in addition to honey production. Pesticide exposure may be of the main causes leading to CCD by weakening the immune system of honeybees and impairing their immune responses. Nosemosis diseases caused by Nosema spp. may have a significant contribution to CCD when bees are exposed to different pesticides simultaneously. Multiple risk factors are assessed in this study including the most used neonicotinoids worldwide, imidacloprid and amitraz which is the pesticide used directly in contact with honeybees to treat mite infection. Th effect of these pesticides is evaluated at the level of immune stimulation by zymosan A to mimic Nosema infection. The effect of pesticides on antimicrobial cells products, cellular responses and related genes' expression are demonstrated
Childs, Peter Geoffrey. "Cellular mechanotransduction : development of a nanovibrational bioreactor for cellular stimulation". Thesis, University of the West of Scotland, 2016. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.739388.
Pełny tekst źródłaTye, Gee Jun. "Combined adjuvant for stimulation of cellular immunity". Thesis, King's College London (University of London), 2012. https://kclpure.kcl.ac.uk/portal/en/theses/combined-adjuvant-for-stimulation-of-cellular-immunity(b1be07ae-b8d4-40a8-9258-bc3e3413df9d).html.
Pełny tekst źródłaEL, GHARBI NAJWA. "Facteurs influencant la migration cellulaire chez deux souches de souris genetiquement selectionnees pour leur forte (hi/pha) ou faible (lo/pha) reponse a la phytohemagglutinine (pha). Etablissement d'un hybridome produisant le(s) facteur(s) de stimulation et caracterisation biochimique de cette lymphokine". Paris 6, 1990. http://www.theses.fr/1990PA066492.
Pełny tekst źródłaPawlak, Géraldine. "Le Colony-Stimulating Factor-1 Receptor (CSF-1R) induit un signal spécifique de différenciation vers la voie monocytaire, dans des cellules hématopoïétiques pluripotentes murines". Lyon 1, 1999. http://www.theses.fr/1999LYO10169.
Pełny tekst źródłaBarucha-Kraszewska, Justyna. "Experimental and stimulation analyses of fluorescent solvent relaxation process in biomembranes : Inflence of ions and molecular interpretation of the dye dynamics". Thesis, Besançon, 2012. http://www.theses.fr/2012BESA3010/document.
Pełny tekst źródłaMany biologically important processes and phcnomena in lipid membranes are still not fully understood. The presence of ions and water molœules has a significant influence on the structural and dynamical properties of lipid bilayers. Fluorescent techniques are versatile tools for studying the lipid membranes, because the fluorescence emission is strongly sensitive to dye environment. We have conducted fluorescent solvent relaxation (SR) experiments to explore the hydration and mobility properties in lipid membranes in the presence of different chaotropic ions. We have also carried out Quantum Mechanical (QM) calculations and Molecular Dynamics (MD) simulations for supporting the SR experiments. SR experiments show that small cation (Na+) is attracted to the membrane and increases rigidity ofbilayer, while larger cations (NH/, Cs+) should not. Large anions (CI04·, SCN') adsorl, at the membrane interface more easily than smaller ones (Cl') and significantly change tl!e mobility and hydration of the headgroup region oflipid bilayer. SR study ofhydrophobic part of the membrane show that SR processes are complex there and reflect botl!: faster, intramolecular (torsional relaxation or fonnation of charge transfer state) and slower, intermolecular (SR) relaxation processes. QM calculatiom were used to create force-field for three fluorescent dyes (Prodan, Laurdan and C-laurdan). MD simulations allow detennining position of the dye in the lipid membrane in the ground state and after excitation and reproduce correctly SR timescale- ps in water and ns in the membrane. MD simulations extend the capabilities of SR method and allow observing the behaviour of individual molecules
Magret, Valérie. "Stimulation d'activites phospholipase a2 cellulaires par les lipoproteines de haute densite". Lille 2, 1994. http://www.theses.fr/1994LIL2P260.
Pełny tekst źródłaDajas-Bailador, Federico. "Cellular responses elicited by stimulation of neuronal nicotinic acetylcholine receptors". Thesis, University of Bath, 2002. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.392053.
Pełny tekst źródłaVacher, Jonathan. "Synthèse de textures dynamiques pour l'étude de la vision en psychophysique et électrophysiologie". Thesis, Paris Sciences et Lettres (ComUE), 2017. http://www.theses.fr/2017PSLED005/document.
Pełny tekst źródłaThe goal of this thesis is to propose a mathematical model of visual stimulations in order to finely analyze experimental data in psychophysics and electrophysiology. More precisely, it is necessary to develop a set of dynamic, stochastic and parametric stimulations in order to exploit data analysis techniques from Bayesian statistics and machine learning. This problem is important to understand the visual system capacity to integrate and discriminate between stimuli. In particular, the measures performed at different scales (neurons, neural population, cognition) allow to study the particular sensitivities of neurons, their functional organization and their impact on decision making. To this purpose, we propose a set of theoretical, numerical and experimental contributions organized around three principal axes: (1) a Gaussian dynamic texture synthesis model specially crafted to probe vision; (2) a Bayesian observer model that accounts for the positive effect of spatial frequency over speed perception; (3) the use of machine learning techniques to analyze voltage sensitive dye optical imaging and extracellular data. This work, at the crossroads of neurosciences, psychophysics and mathematics is the fruit of several interdisciplinary collaborations
Aryaei, Ashkan. "Mechanical Properties of Bio-nanocomposites and Cellular Behavior under Mechanical Stimulation". University of Toledo / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1398361357.
Pełny tekst źródłaSieni, Elisabetta. "Biomedical applications of electromagnetic fields: human exposure, hyperthermia and cellular stimulation". Doctoral thesis, Università degli studi di Padova, 2011. http://hdl.handle.net/11577/3421649.
Pełny tekst źródłaI campi elettromagnetici sono diffusi in molti ambienti industriali e residenziali. Alcune delle più comuni sorgenti di campo elettromagnetico sono le radiazioni solari, la corrente elettrica che alimenta gli elettrodomestici (luci, televisore, frigorifero, ecc.) e le antenne per le telecomunicazioni. Negli ambienti industriali i campi elettrici e magnetici sono utilizzati per la fusione e il trattamento dei metalli, in particolare alcuni dispositivi per la saldatura possono generare campi elettromagnetici di intensità elevata. In ambiente residenziale la diffusione del piano di cottura a induzione ha aumentato la possibilità di esposizione della popolazione a campi magnetici che potrebbero essere intensi. Inoltre i campi elettromagnetici possono essere utilizzati a scopo medico in alcune terapie. Questa tesi analizza l'interazione tra campi elettromagnetici e tessuti biologici. È da notare che l'interazione del campo magnetico con un materiale conduttore produce correnti indotte che circolano nel materiale e producono calore per effetto Joule. L'applicazione più importante di questo fenomeno è il trattamento e la fusione dei metalli che hanno una elevata conducibilità elettrica (dell'ordine dei milioni di Sm-1) ed alta permeabilità magnetica relativa. Nonostante i tessuti del corpo umano siano cattivi conduttori elettrici (conducibilità dell'ordine l'unità o più bassa e una permeabilità magnetica relativa unitaria), la densità di corrente indotta può causare la contrazione muscolare. L'intensità di queste correnti indotte dipende dall'intensità del campo magnetico che le genera e il loro effetto è percepibile se superano la soglia di stimolazione dei nervi o dei muscoli. Quindi, ogni apparecchiatura che utilizza una corrente elettrica produce un campo magnetico che può generare correnti indotte nei tessuti biologici. Alcune norme regolano il massimo valore del campo elettromagnetico a cui ogni persona può essere esposta. Tra le apparecchiature che generano campi magnetici questo lavoro analizza le saldatrici ad arco e a resistenza e i piani di cottura a induzione. Al fine di valutare l'esposizione umana al campo magnetico sotto i 100 kHz, si valuta l’induzione magnetica e la corrente indotta in opportuni volumi che simulano il corpo umano mediante il metodo degli Elementi Finiti. La corrente indotta calcolata con i modelli semplificati del corpo umano è stata confrontata con quella calcolata utilizzando modelli che descrivono con precisione i tessuti del corpo umano. Campi elettrici e magnetici possono inoltre essere utilizzati in alcune applicazioni mediche. Ad esempio, il campo magnetico ed elettrico possono trovare impiego nella terapia dei tumori. Esempi sono l'ablazione termica dei tessuti o il riscaldamento di zone localizzate (laser, antenne a radiofrequenza, thermoseed, ecc.). Una tecnica di nuova generazione è l’ipertermia magneto fluida, la cui idea originaria risale agli anni ‘50, ma il primo prototipo è della fine degli anni novanta. Questa tecnica utilizza nanoparticelle magnetiche inserite nelle aree da trattare. Le nanoparticelle sono riscaldate per mezzo di un campo magnetico tempo variante esterno di frequenza e di intensità adeguate e agiscono come una fonte interna di calore. In questo caso la temperatura raggiunta dai tessuti deve raggiungere la soglia terapeutica (42-43°C per l'ipertermia o superare i 60 °C per l'ablazione termica). Il campo elettrico può essere utilizzato anche per stimolare diverse aree del cervello. Un primo studio mostra alcuni risultati di simulazione ottenuti sia in un cervello umano sia di ratto. Inoltre, per questo esempio è stato sviluppato un set up sperimentale per misure in vivo nei tessuti della testa di un ratto. Il calcolo del campo termico ed elettromagnetico è stato risolto utilizzando il Metodo degli Elementi Finiti. Inoltre sono stati implementati alcuni algoritmi per la soluzione di problemi di accoppiamento magnetico e termico e un codice per la procedura di ottimizzazione. Il codice di ottimizzazione, di tipo Evolution Strategy, è stato implementato all'interno di un software commerciale per risolvere problemi elettromagnetici e termici mediante il metodo degli Elementi Finiti. Per la soluzione delle equazioni di Maxwell per il calcolo del campo magnetico, l’induzione magnetica, la densità di corrente indotta e il campo elettrico sono state utilizzate diverse formulazioni, mentre il problema termico è stato risolto utilizzando l'equazione di trasferimento del calore, includendo il termine Pennes che descrive l'effetto della perfusione sanguigna. I codici di ottimizzazione sono stati utilizzati principalmente per la progettazione di un dispositivo per l’ipertermia magneto fluida. Per un primo disegno della sorgente di campo magnetico si è ottimizzata l’uniformità del campo magnetico, sotto l'ipotesi che le nanoparticelle magnetiche fossero distribuite uniformemente nei tessuti. In seguito il codice di ottimizzazione è stato utilizzato per cercare l'uniformità della temperatura nelle zone da trattare, e quindi è si è risolto un problema magnetico-termico accoppiato. In questo caso il passaggio dal problema magnetico a quello termico ha richiesto il calcolo della densità di potenza generata dalle nanoparticelle magnetiche a partire dall'intensità del campo magnetico. In questo caso si è utilizzata una relazione analitica che valuta la potenza a partire dalla temperatura istantanea dei tessuti, le caratteristiche fisiche delle nanoparticelle magnetiche e l’intensità e la frequenza del campo magnetico. L'ottimizzazione dell’uniformità della temperatura nella zona trattata, anche in termini di rateo di temperatura, può essere vista come progettazione sia della sorgente del campo magnetico sia del magnetofluido (dimensioni e concentrazione delle nanoparticelle) . Entrambi questi aspetti sono stati indagati. Infine è stato valutato l’effetto della reale distribuzione delle nanoparticelle nei tessuti tumorali sulla disuniformità di temperatura legata alla disuniformità della concentrazione delle nanoparticelle. In questo caso, per limitare la disuniformità di temperatura correlata alla concentrazione delle nanoparticelle, si è sviluppato un algoritmo per l'ottimizzazione dei punti di iniezione in situ delle nanoparticelle. Infine è stata studiata la distribuzione del campo elettrico creato da una differenza di potenziale applicata alla scatola cranica per valutare la fattibilità di raggiungere le strutture interne del cervello. Il segnale di tensione utilizzato è a 4 MHz, una frequenza non usuale per la strumentazione normalmente utilizzata per misurare i potenziali elettrici in vivo su animali. Per confrontare la tensione calcolata con i codici numerici con quella misurata all'interno del tessuto cerebrale usando micropipette di vetro, è stato studiato un set up di misura. La micropipetta alla frequenza di 4 MHz ha impedenza differente rispetto quella che si ha nel normale uso dello strumento (frequenze inferiori a 1 kHz). Mediante l’esperimento progettato si sono ottenute delle curve di taratura per convertire il segnale misurato con la micropipetta e l’oscilloscopio. Tali curve tengono conto della reale impedenza della micropipetta. Queste misurazioni sono state utilizzate per validare le simulazioni numeriche del campo elettrico. I principali risultati di questa tesi sono i modelli di organismi viventi implementati per valutare le interazione dei campi elettromagnetici con i tessuti biologici. In particolare, per risolvere i problemi elettromagnetici e di accoppiamento magnetico e termico sono state utilizzate diverse formulazioni. Inoltre, per la progettazione dei dispositivi magnetici, la pianificazione del trattamento (posizionamento della sorgente di campo magnetico in funzione paziente) e la composizione del magneto fluido (dimensioni e concentrazione delle nanoparticelle) sono stati utilizzati algoritmi di ottimizzazione.
Pelletier, Simon. "Étude des mécanismes d’actions cellulaires et physiologiques de la stimulation transcrânienne à courant direct". Master's thesis, Université Laval, 2015. http://hdl.handle.net/20.500.11794/25758.
Pełny tekst źródłaTranscranial direct current stimulation (tDCS) is a non-invasive electrostimulation technique studied used in clinical studies. My master's project, presented here, aimed to deepen our knowledge of the mechanisms of action underlying these effects by the application of direct current electric fields (DCEFs), which are produced during the stimulation, on neuronal, microglial and astrocytic cells and ventral tegmental area in vitro. The results presented suggest that DCEFs promote axonal regeneration in neurons. They also put forward that its usage does not reduce the activation state of activated microglial cells, but can increase it in quiescent microglial cells at high intensity. Finally, the astrocytes are strongly elongated perpendicularly to the DCEF. The results thus support the neuroregenerative potential it was attributed and its modification would not modify the microglia activation state.
Kelps, Kristen. "Molecular and Cellular Characterization of Dopamine Neuron Stimulating Peptides". UKnowledge, 2013. http://uknowledge.uky.edu/neurobio_etds/6.
Pełny tekst źródłaLiljemalm, Rickard. "Infrared Laser Stimulation of Cerebral Cortex Cells - Aspects of Heating and Cellular Responses". Doctoral thesis, KTH, Neuronik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-138511.
Pełny tekst źródłaHeller, Martin [Verfasser]. "Design of cell adhesive and angiogenic titanium surfaces for cellular stimulation / Martin Heller". Mainz : Universitätsbibliothek Mainz, 2013. http://d-nb.info/103372503X/34.
Pełny tekst źródłaThyagarajan, Sridevi. "ADRENERGIC STIMULATION IN ACUTE HYPERGLYCEMIA: EFFECTS ON CELLULAR AND TISSUE LEVEL MURINE CARDIAC ELECTROPHYSIOLOGY". UKnowledge, 2018. https://uknowledge.uky.edu/cbme_etds/49.
Pełny tekst źródłaMichaud, Jean-Philippe. "Phagocytes mononucléaires dans la maladie d'Alzheimer : caractérisation et stimulation de mécanismes cellulaires promouvant l'élimination de bêta-amyloïde". Doctoral thesis, Université Laval, 2015. http://hdl.handle.net/20.500.11794/25913.
Pełny tekst źródłaLa maladie d’Alzheimer (MA) est la plus fréquente cause de démence mondialement et son incidence augmente en parallèle au vieillissement de la population. La pathogenèse de cette maladie neurodégénérative, actuellement sans traitement curatif, est associée à l’accumulation de bêta-amyloïde (Aβ) dans le parenchyme et la vasculature du cerveau en réponse à l’élimination déficiente de ce peptide neurotoxique. Des évidences épidémiologiques et expérimentales soulignent le rôle crucial du système immunitaire inné dans la MA. Plus précisément, plusieurs études suggèrent que les phagocytes mononucléaires (microglies, monocytes et macrophages cérébraux) constituent des cellules pivots pour combattre l’accumulation d’Aβ. Les études incluses dans cette thèse de doctorat avaient comme objectif d’accroitre les connaissances concernant le rôle des phagocytes mononucléaires dans la pathologie du modèle murin APP/PS1 de la MA. Un nombre croissant d’études indique que les Toll-like receptors (TLRs) seraient critiques pour la clairance d’Aβ par les phagocytes mononucléaires. Nous avons donc étudié le rôle de la protéine adaptatrice myeloid differentiation factor 88 (MyD88), qui permet la transduction du signal intracellulaire de la plupart des TLRs. Nous avons observé une augmentation des niveaux d’Aβ solubles et une aggravation des déficits cognitifs dans les souris APP/PS1 avec une signalisation MyD88 défectueuse, vraisemblablement suite à une réduction de la phagocytose des phagocytes mononucléaires et une coordination défaillante de la réponse immunitaire innée. La stimulation des TLRs pourrait ainsi avoir un grand potentiel thérapeutique pour la MA. Nous avons démontré que des injections systémiques répétées du ligand TLR4 monophosphoryl lipid A (MPL) dans les souris APP/PS1 ont mené à une réduction significative des niveaux d’Aβ et une amélioration des fonctions cognitives. Le MPL induit une forte réponse phagocytique des phagocytes mononucléaires tout en générant une réaction inflammatoire modérée. Finalement, en utilisant la microscopie intravitale biphotonique, nous avons dévoilé que les monocytes patrouilleurs en état basal sont attirés et rampent sur la face luminale de veines contenant de l’Aβ, capturent l’Aβ et ont la capacité de regagner à nouveau la circulation sanguine. L’ablation sélective des monocytes patrouilleurs dans les souris APP/PS1 a induit une augmentation significative des niveaux d’Aβ dans le cortex et l’hippocampe. Ensemble, ces données démontrent que les phagocytes mononucléaires sains et fonctionnels peuvent promouvoir l’élimination d’Aβ et constituent une cible thérapeutique prometteuse pour la MA.
Alzheimer’s disease (AD) is the most common cause of dementia worldwide and its incidence is rising in parallel with the aging population. The pathogenesis of this neurodegenerative disease, currently without curative treatment, is associated with the accumulation of amyloid-β (Aβ) in the brain parenchyma and cerebral vasculature in response to the impaired clearance of this neurotoxic peptide. Epidemiological and experimental evidence underline the crucial role of the innate immune system in AD. More precisely, several studies suggest that mononuclear phagocytes (microglia, monocytes and cerebral macrophages) constitute pivotal cells to fight the accumulation of Aβ. The studies enclosed in this doctoral thesis intended to better understand the role of mononuclear phagocytes on the pathology of the APP/PS1 mouse model of AD. Accumulating evidence indicates a critical role of Toll-like receptors (TLRs) in the clearance of Aβ by mononuclear phagocytes. We thus investigated the role of the myeloid differentiation factor 88 (MyD88), which is the adaptor protein for most of these innate immune receptors, transducing the intracellular signal from TLRs to the nucleus. We observed increased soluble levels of A oligomers and enhanced cognitive deficits in APP/PS1 mice with impaired MyD88 signalling, likely through reduced phagocytosis of mononuclear phagocytes and an impaired coordination of the innate immune response. Compounds that stimulate TLRs to clear Aβ may therefore have great therapeutic potential in AD patients. We demonstrated that repeated systemic injections of the TLR4 ligand monophosphoryl lipid A (MPL) in APP/PS1 mice led to a significant reduction in Aβ load and improved cognitive function. MPL induced a potent phagocytic response by mononuclear phagocytes while triggering a moderate inflammatory reaction. Finally, using live intravital two-photon microscopy, we discovered that patrolling monocytes in steady state are attracted and crawl onto the luminal walls of Aβ-positive veins, uptake Aβ and are able to circulate back into the bloodstream. Selective removal of patrolling monocytes in APP/PS1 mice induced a significant increase of Aβ load in the cortex and hippocampus. Overall, these studies demonstrate that healthy and functional mononuclear phagocytes can promote the elimination of Aβ and constitute a promising therapeutic target for AD.
Gaci, Mohammed. "Radiothérapie interne (électrons Auger) par stimulation gamma résonante Mössbauer : chimère ou réalité ? : Etudes physico-chimiques, cellulaires et biomoléculaires". Poitiers, 2002. http://www.theses.fr/2002POIT2328.
Pełny tekst źródłaMills and al (1988) proposed to treat superficial tumours a new type of therapy using electrons Auger emission induced by Mössbauer effect. This technique is a combination of a vector to target cellular tumour DNA (here bleomycin (BLM)) and an Auger emitter ( a Mössbauer isotope:57Fe). In this work we define the place of this new therapy, and we show that only seven Mössbauer isotopes can be used. We study chemically the BLM-Fe complex. After, a Mössbauer spectroscopy analysis of the BLM-Fe and BLM-Fe-DNA complex is performed and found velocities to achieve the resonance effect. The survival rates studies on two cellular types (SW480 and E. Coli) found any efficacy. A plasmidic model is developed. We enhance: the number of BLM molecules (1012 and 1013), the non-recoil f-factor, the irradiation dose and we don't found any efficacy defined as double strands breaks (DSB). A Monte Carlo study using BLM-Fe complex with a peace of DNA plasmid is built. This model permitted to show a great efficacy in terms of DSB. Those results are confirmed by a model using BLM-55Fe (radioactive isotope) on PGEM4Z plasmid. It can be conclude that Mössbauer effect is not the appropriate technique in radiotherapy
Paraskevopoulos, Yannis. "Utilisation des enveloppes cellulaires de levure pour la stimulation de la fermentation malolactique interprétation de leur mode d'action /". Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb37617284p.
Pełny tekst źródłaPham, Michael N. "Erythropoietin Stimulation of Mitochondrial Protein Content - A Potential Mechanism through Direct Binding of Erythropoietin Receptor and AMP-Activated Protein Kinase". Diss., The University of Arizona, 2014. http://hdl.handle.net/10150/321354.
Pełny tekst źródłaLough, Kristen. "THE EFFECT OF CHOLESTEROL ON THE OSTEOBLAST RESPONSIVENESS TO HYDRODYNAMIC PRESSURE STIMULATION". UKnowledge, 2015. http://uknowledge.uky.edu/cbme_etds/27.
Pełny tekst źródłaKoh, Kar Mun. "Effects of Alternating Current Electrical Stimulation on the Cellular Chemistry and Proliferation of C2C12 Muscle Cells". Thesis, North Dakota State University, 2016. https://hdl.handle.net/10365/28058.
Pełny tekst źródłaTang, Lifei. "Effects of Neuronal Nitric Oxide Synthase Signaling on Myocyte Contraction during Beta-Adrenergic Stimulation". The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1385336408.
Pełny tekst źródłaGutwein, Amanda Brooke. "Characterization of Stimulation-induced Volume Changes in the Ca1Region of Rat Hippocampus Slices". Wright State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=wright1369704794.
Pełny tekst źródłaMiquel, Fabre Françoise. "Propriétés érythroagglutinantes et mitogéniques d'une lectine (DLA) extraite de Dolichos Lablab L. Caractérisation de ses récepteurs membranaires impliqués dans la stimulation lymphocytaire". Montpellier 1, 1989. http://www.theses.fr/1989MON13504.
Pełny tekst źródłaNizza, Suzanne Josette Taghap. "The Role of Dendritic Cell Subsets in Cross-presentation and Stimulation of Homing Marker Expression". Thesis, Harvard University, 2013. http://dissertations.umi.com/gsas.harvard:11224.
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