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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.
41

The Effect of Dietary Changes on Microbial Populations within the Gastrointestinal Tract of the Giant Panda (Ailuropoda Melanoleuca)

Williams, Candace Lareine 06 August 2011 (has links)
Both in-situ and ex-situ giant pandas (Ailuropoda melanoleuca), display shifts in bamboo species and part preference throughout the year. The effects of this shifting preference on gastrointestinal (GIT) microbiota were observed using traditional culturing methods to characterize normal GIT microflora from fecal samples and behavioral feeding data of adult male and female pandas over a fourteen-month period. Linear and quadratic fits were used to determine any significant relationships between the time of year and part preference on the GIT microflora (P<0.05). Significant values for time of year were observed with the linear fit in total aerobes (P-value=0.0368), streptococci (P-value=0.0120), and lactobacilli (P-value=0.0166) and quadratic fits in streptococci (P-value=0.0382) and Bacteroides spp. (P-value=0.0134) at á=0.05. Significant linear relationships were observed with part preference and lactobacilli and Bacteroides spp., P-values of 0.0028 and 0.0030, respectively, indicating that part preference and time of year may affect the flux of panda GIT microflora.
42

Cervical MUC5B and MUC5AC are Barriers to Ascending Pathogens During Pregnancy / 子宮頸管内のMUC5BとMUC5ACは妊娠中の上行性感染を防御する

Ueda, Yusuke 23 March 2023 (has links)
京都大学 / 新制・課程博士 / 博士(医学) / 甲第24514号 / 医博第4956号 / 新制||医||1064(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 長尾 美紀, 教授 中川 一路, 教授 杉田 昌彦 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
43

Role of Matrix Metalloproteinases in Acrolein-Induced Mucin 5 (Subtype A and C) Increase

Deshmukh, Hitesh S. 03 April 2006 (has links)
No description available.
44

Physique de la dynamique mucociliaire : dispositif d'étude de la migration cellulaire 3D : application à l'asthme et à la BPCO / Physics of mucociliary dynamics : device for studying the 3D cell migration : application to asthma and COPD

Khelloufi, Mustapha Kamel 21 October 2015 (has links)
Ce travail consiste à apporter une approche différente basée sur la physique pour l'étude des maladies respiratoires.La première partie de cette étude concerne la dynamique mucociliaire avec une application à l'asthme sévère et la BPCO. Nous avons décrit les mécanismes physiques du transport de mucus basés sur l'analyse détaillée de l'activité ciliaire sur un épithélium reconstitué in vitro à partir de biopsies endo-bronchiques humaines. Nous avons montré que la distance à laquelle le mucus ou le fluide newtonien pouvaient être transportés dépendait directement du taux de couverture de l'épithélium par les touffes de cils actives. Nous avons ensuite mis en avant le rôle majeur du mucus viscoélastique sur la coordination de la direction des battements ciliaires pour un transport macroscopique. La fréquence de battement des cils joue sur la vitesse du transport du fluide. Enfin, nous avons montré que l'altération de la clairance observée dans l'asthme sévère et la BPCO est due au manque drastique de cils, tandis que les propriétés rhéologiques du mucus restent inchangées dans notre modèle.La deuxième partie traite de la migration cellulaire dans un environnement biomimétique 3D. Nous avons mis au point un microdispositif pour la caractérisation de la migration des cellules par chimiotaxie. Nous avons validé le modèle en utilisant des cellules immunitaires soumises à des gradients de substances chimio-attractantes et un premier test du rôle inflammatoire a été effectué. / This work consists to bring a different approach based on physics to study the respiratory diseases.First, study of mucociliary dynamics with an application on severe asthma and COPD was investigated. We have described the physical mechanisms of mucus transport based on the detailed analysis of ciliary activity on an in vitro reconstituted epithelium obtained from human endo-bronchial biopsies. We have shown that the distance at which mucus or Newtonian fluid could be transported is directly dependent on the epithelium coverage rate by the active cilia tufts. Then, we raised the important role of the viscoelastic mucus on the coordination of the ciliary beat direction for a macroscopic transport. The cilia beat frequency plays on transport fluid velocity. Finally, we have shown that altered clearance observed in severe asthma and COPD is due to the drastic lack of cilia, while the rheological properties of mucus remains unchanged in our model.The second part of this work was to look at cell migration in a bio-mimetic 3D environment. We have developed a micro-device for characterization of cell migration by chemotaxis. We validated the model using immune cells under a chemo-attractant substances gradients and a first test of inflammatory role has been completed.
45

Fonctions in vivo de la mucine Muc5b : création et caractérisation d'une lignée transgénique rapporteur Muc5b-GFP / In vivo functions of the Muc5b mucin : creation and characterization of a Muc5b‑GFP transgenic mouse reporter

Portal, Céline 05 December 2016 (has links)
MUC5B, une des 5 mucines gélifiantes chez les mammifères, constitue la matrice de gels de mucus et est responsable des propriétés visco-élastiques de ces gels. Cette macromolécule est sécrétée par des cellules caliciformes dont la densité reflète l'homéostasie des épithéliums sécrétoires.L'objectif principal de ce travail de thèse était la création et la caractérisation d'une souris transgénique afin de suivre facilement la production in vivo de Muc5b. Le second objectif était de montrer, chez des souris mucoviscidosiques CftrΔF508, qu'une nutrition enrichie en acides gras polyinsaturés à longues chaînes (n-3) module la production de la mucine Muc5b, confirmant des résultats précédemment publiés sur la régulation transcriptionnelle du gène Muc5b chez des souris de type sauvage par ce régime alimentaire.Une souris transgénique Muc5b-GFP a été créée par insertion d'une séquence codant la GFP (pour « Green Fluorescent Protein ») à la place du codon Stop de Muc5b. Le profil d'expression de Muc5b a été déterminé ex vivo sur tissus et chez la souris anesthésiée. Muc5b est produit dans l'oreille moyenne, l’œil, la cavité nasale, la trachée, la vésicule biliaire, le cervix, ainsi que dans le poumon embryonnaire à E12,5. Nous apportons la preuve de concept que Muc5b-GFP est un biomarqueur de la densité des cellules à mucus dans un modèle de syndrome de l’œil sec où nous mesurons, chez la souris anesthésiée, une diminution de la densité en cellules caliciformes qui est restaurée par application topique d'interleukine 13. La souris Muc5b-GFP est donc un modèle pré-clinique pour suivre la production de la mucine et la densité de cellules caliciformes. Dans le modèle murin CftrΔF508, nous montrons qu'une supplémentation à long terme en acides gras polyinsaturés à longues chaînes (n-3) n'influence pas le taux d'expression de Muc5b suite à une inflammation pulmonaire aiguë, mais améliore l'histologie pulmonaire et module la réponse inflammatoire. / MUC5B, one of the 5 gel-forming mucins in mammals, is part of the mucus gels and responsible of the visco-elastic properties of these gels. The density of goblet cells, which secrete this macromolecule, reflects the homeostasis of secretory epitheliums.The main goal of this thesis was the creation and characterization of a transgenic mouse to easily follow in vivo the production of Muc5b. The second goal was to show that, as previously reported by the laboratory in wild-type mice, a (n-3) long chain polyunsaturated fatty acid enriched diet modulates the production of Muc5b in the cystic fibrosis mouse model CftrΔF508.A Muc5b-GFP transgenic mouse was created by replacing the Stop codon of Muc5b with a GFP (Green Fluorescent Protein) coding sequence. Muc5b expression pattern was studied ex vivo in tissues and in anaesthetized mouse. Muc5b is produced in middle ear, eye, nasal cavity, trachea, gallbladder, cervix, and in embryonic lung at E12.5. As a proof-of-concept, we show that Muc5b-GFP is a biomarker of goblet cell density in a dry eye model. In anaesthetized mice, we measured a decreased goblet cell density after dry eye induction, which was restored by interleukin 13 topical application. Muc5b-GFP mouse is a preclinical model to follow the mucin production and goblet cell density. In the cystic fibrosis mouse model CftrΔF508, we show that a long term (n-3) long chain polyunsaturated fatty acid supplementation has no effect after an acute pulmonary inflammation on the Muc5b expression level, but induces an improvement of lung histology and a modulation of the inflammatory response.
46

Nitrate, Nitrite and Nitric Oxide in Gastric Mucosal Defense

Petersson, Joel January 2008 (has links)
<p>The human stomach normally contains high levels of bioactive nitric oxide (NO). This NO derives from salivary nitrate (NO<sub>3</sub><sup>-</sup>) that is converted to nitrite (NO<sub>2</sub><sup>-</sup>) by oral bacteria and thereafter non-enzymatically reduced in the acidic gastric lumen to NO. Nitrate is a common component in vegetables, and after ingestion it is absorbed in the small intestine. Interestingly, circulating nitrate is then concentrated by the salivary glands. Hence, intake of nitrate-rich vegetables results in high levels of NO in the stomach. The physiological effects of the high concentration of NO gas normally present in the gastric lumen have been hitherto unknown, and the present investigations were therefore conducted to address this issue.</p><p>NO produced in the gastric lumen after nitrate ingestion increased gastric mucosal blood flow and the thickness of the firmly adherent mucus layer in the stomach. The blood flow and mucus layer are essential defense mechanisms that protect the mucosa from luminal acid and noxious agents. Nonsteroidal antiinflammatory drugs (NSAID) are commonly prescribed and effective drugs for treating pain and inflammation, but are associated with severe gastrointestinal side effects. We demonstrated that a nitrate-rich diet protects against NSAID-induced gastric damage, as a result of the increased formation of NO in the stomach. We also showed that the gastroprotective effect attributed to nitrate depended completely on conversion of nitrate to nitrite by the bacterial flora colonizing the tongue, and that the oral microflora is therefore important in regulating physiological conditions in the stomach.</p><p>In summary, this thesis challenges the current dogma that nitrate intake is hazardous, and on the contrary suggests that dietary nitrate plays a direct role in regulating gastric homeostasis. It is likely that a sufficient supply of nitrate in the diet together with the oral microflora is essential for preventing pathological conditions in the gastrointestinal tract.</p>
47

Host-parasite interactions of coral reef fish / Intéractions hôte-parasite chez les poissons des récifs coraliens

Reverter, Miriam 21 October 2016 (has links)
Les parasites sont une partie très importante des écosystèmes, néanmoins, dans certains cas tels que l’aquaculture ils causent des épidémies. Dans cette thèse j’ai étudié les interactions hôte-parasite chez les poissons coralliens, dans les milieux naturels et les milieux aquacoles. J’ai étudié l’arrangement des communautés de 13 espèces de monogènes de 34 espèces de poissons papillon dans l’Indo-Pacifique. Les résultats montrent qu’il existe un patron de distribution stable des espèces, ce qui, combiné avec les résultats de l’étude biogéographique, suggère que la spécificité parasitaire observée a pu se développer tout au long des épisodes biogéographiques passés. Notamment, seule une espèce, Chaetodon lunulatus, n’est jamais parasitée. J’ai étudié le mucus des poissons qui est décrit comme la première ligne de défense contre des agressions externes, pour analyser quels facteurs de C. lunulatus pourraient être reliés à l’absence des parasites. Le microbiome et le métabolome du mucus branchial des poissons papillons montrent une grande diversité. C. lunulatus présente une plus grande abondance de Fusobactéries qui est corrélée avec une surexpression de peptides pouvant dériver de la β-hémoglobine. La purification, la synthèse et l’évaluation des activités antiparasitaires des peptides sont en cours au laboratoire. J’ai aussi étudié l’utilisation des plantes médicinales comme alternative à des traitements chimiques dans l’aquaculture. J’ai testé l’activité antibactérienne et immunostimulatrice de plusieurs plantes et algues polynésiennes. L’algue rouge Asparagopsis taxiformis montre de fortes activités antibactériennes sur Vibrio harveyi et Tenacibaculum maritimum et induit une augmentation de l’expression de deux gènes liés à l’immunité chez Platax orbicularis. / Fish parasites are an important part of ecosystems, however, in certain cases such as in aquaculture they can cause severe disease outbreaks. In this thesis I have studied host-parasite interactions in coral reef fishes, both in the natural and culture environments. I have studied the distribution of 13 dactylogyrid species from 34 butterflyfishes in the Indo West-Pacific. Composition of dactylogyrid communities was host specific and together with the biogeography results, where a turnover in the main Haliotrema species was observed, suggest that parasite specificity might result from host-parasite coevolution derived from past biogeographical episodes. Only one butterflyfish species, Chaetodon lunulatus, was never found parasitized by gill monogeneans. I have studied the butterflyfish mucus, which is the first barrier against pathogens, to investigate the C. lunulatus factors that might be related to the monogenean absence. Butterflyfish gill microbiome and metabolome revealed a high diversity. C. lunulatus presented a significantly higher abundance of Fusobacteria which was correlated to a higher expression of potentially derived β-hemoglobin peptides. Synthesis and evaluation of the peptide antiparasitic activities are being performed in the laboratory. I have also studied the use of medicinal plants as an alternative to chemotherapy in fish aquaculture. I investigated the antibacterial and immunostimulant activities of several local Polynesian plants and algae, and I found that Asparagopsis taxiformis displayed a potent antibacterial activity against Vibrio harveyi and Tenacibaculum maritmum and increased expression of two immune-related genes in Platax orbicularis.
48

Nitrate, Nitrite and Nitric Oxide in Gastric Mucosal Defense

Petersson, Joel January 2008 (has links)
The human stomach normally contains high levels of bioactive nitric oxide (NO). This NO derives from salivary nitrate (NO3-) that is converted to nitrite (NO2-) by oral bacteria and thereafter non-enzymatically reduced in the acidic gastric lumen to NO. Nitrate is a common component in vegetables, and after ingestion it is absorbed in the small intestine. Interestingly, circulating nitrate is then concentrated by the salivary glands. Hence, intake of nitrate-rich vegetables results in high levels of NO in the stomach. The physiological effects of the high concentration of NO gas normally present in the gastric lumen have been hitherto unknown, and the present investigations were therefore conducted to address this issue. NO produced in the gastric lumen after nitrate ingestion increased gastric mucosal blood flow and the thickness of the firmly adherent mucus layer in the stomach. The blood flow and mucus layer are essential defense mechanisms that protect the mucosa from luminal acid and noxious agents. Nonsteroidal antiinflammatory drugs (NSAID) are commonly prescribed and effective drugs for treating pain and inflammation, but are associated with severe gastrointestinal side effects. We demonstrated that a nitrate-rich diet protects against NSAID-induced gastric damage, as a result of the increased formation of NO in the stomach. We also showed that the gastroprotective effect attributed to nitrate depended completely on conversion of nitrate to nitrite by the bacterial flora colonizing the tongue, and that the oral microflora is therefore important in regulating physiological conditions in the stomach. In summary, this thesis challenges the current dogma that nitrate intake is hazardous, and on the contrary suggests that dietary nitrate plays a direct role in regulating gastric homeostasis. It is likely that a sufficient supply of nitrate in the diet together with the oral microflora is essential for preventing pathological conditions in the gastrointestinal tract.
49

Análise do aparelho mucociliar e das propriedades reológicas do muco respiratório em portadores de câncer pulmonar e extra-pulmonar / Analysis of the respiratory mucus properties in cancer patients concerning the primary site of the disease: pulmonary or extra pulmonary tumors

Souza, Areta Agostinho Rodrigues de 27 November 2009 (has links)
Estudos anteriores (Zayas, 1990) tem sugerido a existência de uma melhor transportabilidade por cílio do muco respiratório de pacientes fumantes que não apresentam câncer de pulmão em comparação com pacientes fumantes com câncer de pulmão e semelhante carga tabágica. Nosso principal objetivo foi verificar esta hipótese. Nós estudamos 16 tabagistas com câncer de pulmão (média carga tabágica = 58,78), 16 tabagistas com câncer extra-pulmonar (média carga tabágica = 53,87) e 11 não Tabagistas com Metástase Pulmonar com indicação de broncoscopia diagnóstica. O muco respiratório foi coletado durante a broncoscopia, usando um pequeno cateter através do canal de aspiração do broncoscopio. A transportabilidade por cílio no palato de rã, ângulo de contato (wetabilidade), transportabilidade pela tosse e viscosidade (cone-plate) e análise morfológica do epitélio respiratório foi realizado. Não foi encontrada diferença estatística entre os pacientes Tabagistas (Câncer de pulmão e Câncer extra-Pulmonar) para os parâmetros de muco estudos. Da mesma forma não foi encontrada diferença estatística nas análises do muco coletado de um lado do tumor comparado com o lado contralateral. Entretanto, encontramos diferença estatística entre os grupos não tabagistas com Metástase Pulmonar e Tabagistas com câncer Pulmonar e Extra-Pulmonar para os parâmetros de Transportabilidade pela Tosse (p = 0,018), Viscosidade 10 rpm (p= 0,021), FEV 1 (L) (p= 0,028) e FEV 1 (%) (p= 0,042) e diferença estatística nos Tabagistas para Correlação entre carga tabágica e idade (p=0,038) e Viscosidade (p= 0,029). Na análise histologica observamos 10 Tabagistas (60% alteração, sendo, 30% metaplasia escamosa; 20% hyperplasia e 10% epitélio com ausência de cílios) e 15 não Tabagistas (40% com alteração histológica sendo 20% destes com metaplasia escamosa e em pacientes com Câncer pulmonar ou Câncer extra-pulmonar). Não teve diferença na composição das mucinas entre os tabagistas. Concluímos que não há diferença entre as propriedades físicas do muco respiratório de Tabagistas com Câncer de Pulmão e Câncer Extra-Pulmonar com similar carga tabágica e que essas alterações das propriedades físicas do muco respiratório e alterações morfológicas, devem-se mais à exposição dose-tempo da fumaça do cigarro ao epitélio respiratório / Previous study (Zayas 1990) has suggested the existence of a better transportability by cilia in respiratory mucus of smoking patients who did not present lung cancer in comparison to lung cancer patients smoking similar packages/year. Our aim was to verify this hypothesis. We studied 16 smoking patients with lung cancer (mean packages/year = 58,78), 16 smoking patients with extra pulmonary cancer (esophagus and head and neck), (mean packages/year = 53,87), and 11 non-smoking patients (metastasis) that underwent diagnostic bronchoscopy. Respiratory mucus was collected during bronchoscopy, using a small catheter passed through the aspiration channel of the bronchoscope. Mucus transportability in frog palate, contact angle (wettability), transportability by cough and viscosity (cone-plate) as well as morphological analysis the respiratory epithelium were performed. No statistical differences were found between smoking patients (lung and extra pulmonary cancer) in the mucus parameters studied. In the same way, no difference was found in the analysis of mucus samples collected from the tumor side compared to contra lateral samples. Nevertheless, statistical difference between Smoking (Lung Cancer and Extra-Pulmonary Cancer) and non Smoking (metastasis Pulmononary) for valous Clearance by cough (p = 0,018), viscosity 10rpm (p=0,021) FEV 1 (L) (p= 0,028) and FEV1 (%) (p=0,042) and statistical difference for correlation between smoking history and age (p=0,038) and viscosity 10 rpm (p= 0,029). The analysis histological of the 10 smoking, observed 60% of cases with alteration histological (30% with squamous metaplasia; 20% with hyperplasia and 10% with epithelium with cilia absence) and 15 non smoking presented 40% of cases with alteration histological (205 with squamous metaplasia in patients with lung cancer or exra-pulmonary cancer. We conclude that there is no difference between the physical properties of the respiratory mucus of smokers with lung cancer and extra-pulmonary cancer with similar packages/year and that changes in physical properties of respiratory mucus and morphological changes, due to more exposure to the dose-time of cigarette smoke in the respiratory epithelium
50

Controle de infecções intramamárias no gado leiteiro usando as propriedades antibacterianas e cicatrizantes do muco de escargots Achatina sp no pré e pós dipping / Control of intramammary infections in dairy cattle using antibacterial and healing properties of the mucus of snails Achatina sp in pre and post dipping

Yokoya, Eugênio 21 May 2010 (has links)
O controle de mastite consiste em um conjunto de medidas de manejo e prevenção da doença em um rebanho, pois estudos realizados em todo estado de São Paulo estimaram um prejuízo de 17% da produção por propriedade devido à mastite considerando perdas como os gastos com tratamentos; descarte de leite; queda na produção; além de perdas por resíduos de antibióticos. O trabalho mostra que a população microbiana da mucosa dos tetos não varia conforme a sua posição no úbere do animal e a identificação dos microorganismos predominantes foram como sendo de Staphylococcus aureus, Micrococcus luteus, Klebsiella pneumoniae e Acinetobacter junii. O objetivo deste trabalho foi determinar a eficácia do muco de escargot nos tetos de vacas leiteiras utilizando-o como \"pré e pós dipping\" e o comparado com a aplicação de solução de iodo, visando à prevenção ou a redução da incidência de infecções intramamárias. O muco de escargot possui uma propriedade antibacteriana bastante efetiva, conhecida como Achacin. Sua ação bactericida ocorre principalmente na fase de crescimento da bactéria agindo como agente quimioterápico. O muco de escargot mostrou ser igualmente eficiente no controle da população de microorganismo presente na superfície dos tetos, quando comparados ao uso da solução de iodo, além de que o seu efeito sobre a pele e mucosa dos tetos foi de deixá-los mais hidratados e com melhor elasticidade evitando rachaduras e focos de infecção, quando comparado ao agente mineral, podendo ser até mesmo um produto alternativo no controle e prevenção de mastite em vacas leiteiras. / The control of mastitis is a set of measures for management and prevention of disease in a herd, because studies from every state of Sao Paulo have estimated a loss of 17% in a property considering losses due to mastitis as spending on treatments; discarded milk, drop in production, and losses due to antibiotic residues. The study shows that the microbial population of the mucosa of the teats doesnt vary according to their position in the animal\'s udder and identification of microorganisms were predominant as Staphylococcus aureus, Micrococcus luteus, Klebsiella pneumoniae and Acinetobacter junii. The objective of this study was to determine the effectiveness of snail mucus teats of dairy cows using it as a \"pre and post dipping\" and compared with the application of iodine solution, aiming at preventing or reducing the incidence of mammary infections. The mucus of snail has a very effective antibacterial property, known as Achacin. Its bactericidal action occurs mainly in the growth of bacteria by acting as a chemotherapeutic agent. The mucus of snail proved to be equally effective in controlling the population of microorganisms present on the surface of the teats, compared to the use of iodine solution, and that its effect on the skin and mucous membrane of the teats was leaving them more hydrated and with improved elasticity avoiding cracks and foci of infection, when compared to mineral agent, which may even be an alternative product in the control and prevention of mastitis in dairy cows.

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