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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.
181

Metabolism of articular cartilage proteoglycans in vitro : effects of synovial membrane products and mechanical pressure

Klämfeldt, Agneta January 1982 (has links)
The effect of synovial membrane products and mechanical pressure upon the metabolism of articular cartilage proteoglycans has been studied in vitro. The degradation of cartilage proteoglycans was studied in an organ culture system and measured as the release of [35S ] sulphate from prelabelled cartilage. The effect of synovial membrane products upon the synthesis of proteoglycans was studied in a chondrocyte monolayer system and the effect of mechanical pressure upon the synthesis of proteoglycans in an organ culture system. In both types of experiments [35S] sulphate was used as precursor. The findings may be summarized as follows 1 Conditioned synovial medium (control-SM) enhanced the degradation and reduced the synthesis of cartilage proteoglycans. In addition the degradation was further enhanced when the synovial tissue had been cultured in the presence of dextran sulphate. 2 Conditioned medium from synovial tissue cultured in the presence of indo-methacin (indo-SM), significantly reduced the synthesis of cartilage proteoglycans in chondrocyte cultures and reduced, although non-significantly, the degradation of proteoglycans in whole cartilage cultures. 3 Addition o f the prostaglandins E1 or E2 (PGE1 or PGE2 ) together with indo-SM to the cartilage cultures greatly enhanced cartilage degradation whereas the addition of PGE1 or PGE2 together with control-SM had no effect compared with that of control-SM alone. 4 Conditioned medium from synovial tissue cultured in the presence of low doses of glucocorticoids reduced cartilage degradation compared with control-SM. However, addition of control-SM together w ith low concentrations of glucocorticoids to the cartilage cultures significantly enhanced cartilage degradation. 5 Conditioned medium from synovial tissue cultured with actinomycin D or cycloheximide did not enhance cartilage degradation compared with cartilage cultured alone. 6 A continuous pressure of approximately 30 kgfcm-2 on cultures of cartilage reduced both the synthesis and the degradation o f cartilage proteoglycans. Although it is difficult to extrapolate from the in vitro to the in vivo situation, it is proposed that some factor(s) from the synovial membrane have the capacity to enhance the degradation and reduce the synthesis o f articular cartilage proteoglycans. From these experiments it cannot be completely excluded that treatm ent of arthritic joints with non-steroidal or streroidal anti-inflammatory drugs may result under certain conditions in enhanced joint damage. It is also suggested that under certain conditions the metabolism o f cartilage proteoglycans could be directly affected by mechanical stress. / <p>Diss. Umeå, Umeå universitet, 1982, härtill 6 uppsatser</p> / digitalisering@umu
182

The influence of the hormonal milieu on functional prostaglandin and oxytocin receptors and their downstream signal pathways in isolated human myometrium

Fischer, Deborah Peninnah January 2010 (has links)
Although prostaglandins (PG) and oxytocin are crucial mediators of uterine contractility, their receptor-mediated effects during the menstrual cycle, pregnancy and labour are not fully understood. The aim of this thesis was to elucidate the functional expression of EP, FP, TP and oxytocin receptors in isolated human myometrium relative to myocyte mRNA and signal transduction pathways. Myometrial samples were obtained from consenting non-pregnant and pregnant donors. Functional techniques were used to determine isometric muscle contractions. Primary uterine myocytes and fibroblasts were cultured at term to identify stimulated changes in calcium (Ca2+), cyclic adenosine monophosphate (cAMP) and mRNA. Myometrial strips exhibited spontaneous contractions, which were most active midcycle under oestrogenic conditions. At this time intrinsic contractility and responsiveness to uterotonins decreased towards the fundus. PGE2 produced bellshaped responses with predominant utero-relaxant effects mediated via the EP2 subtype. Although activity was partially restored by PGE2 through EP3/1 receptors, tissue excitation was more pronounced at FP, TP and oxytocin receptors. Despite high FP mRNA expression, the lower segment uterus was particularly responsive to U46619 and oxytocin at term pregnancy. Even so, Ca2+ mobilisation by oxytocin was greater via principal release from intracellular stores. Incubations with atosiban, progesterone and a rho-kinase inhibitor reduced oxytocin-stimulated Ca2+ transients. EP2 also attenuated oxytocic effects but this appeared to be mediated through cAMP rather than Ca2+ signalling pathways. With advancing labour, intrinsic myogenic activity declined in parallel with oxytocin desensitisation. However, TP-induced contractions were continued in the lower parturient uterus. These findings demonstrate that PG and oxytocin receptor expression are regulated in a hormone-dependent temporal and spatial manner. EP2-mediated cAMP formation appears to promote uterine quiescence, whilst TP receptors may control muscle tonus during parturition. These receptors and their messenger systems represent effective tocolytic targets for uterine hypercontractile disorders, such as dysmenorrhoea and preterm labour.
183

The Effect of Lactobacillus rhamnosus GR-1 Supernatant on Cytokine Production and Prostaglandins in Gestational Tissues

Yeganegi, Maryam 18 January 2012 (has links)
Preterm birth remains a major challenge in obstetrics. It complicates up to 13% of all pregnancies and accounts for approximately 80% of neonatal mortality and morbidity. Bacterial Vaginosis (BV) is associated with a 1.4-fold increased risk of preterm birth. Due to ineffectiveness of antibiotics in preventing preterm labour, probiotics have been proposed to serve as an alternative for treatment of BV and prevention of preterm birth. The objectives of this thesis were to determine 1) the effect of Lactobacillus rhamnosus GR-1 (L. rhamnosus GR-1) supernatant on cytokine profile and prostaglandin (PG)-regulating enzyme expression in lipopolysaccharide (LPS)-stimulated human chorion and placental trophoblast cells from human placentae, 2) the potential signaling pathways through which lactobacilli act and 3) the potential role of immune and placental trophoblast cells in initiating a response to LPS and L. rhamnosus GR-1 treatments. Primary cultures of human placental trophoblast cells were pre-treated with lactobacilli supernatant and then with LPS. In addition, immune cells were removed from cell suspensions using a magnetic purification technique to determine their role in modulating cytokine levels. The expression of pro- and anti-inflammatory cytokines and prostaglandin-regulating enzymes was then determined. We found sex-specific differences in the ability of LPS to increase the output of TNF-α, IL-10, and PTGS2. We also showed that L. rhamnosus GR-1 is able to act through the JAK/STAT and MAPK pathways to increase IL-10 and G-CSF, and independently down-regulates PTGS2 and TNF-α and up-regulates PGDH. The increase in G-CSF and PGDH were only observed in women carrying a female fetus. L. rhamnosus GR-1 may serve as an alternative to antibiotics in preventing some infection/inflammation-mediated cases of preterm birth.
184

The influence of the hormonal milieu on eicosanoid and cytokine production in tissues from the female reproductive tract

Garvin, Joanne Helen January 2012 (has links)
In the human uterus prostaglandins (PG) PGE2, PGD2, PGI2, PGF2α and Thromboxane A2 (TXA2), also termed prostanoids, are synthesised and deactivated to 15-keto PGE2, J2 metabolites, 6-keto-PGF1α, 15-keto PGF2α and TXB2 respectively. However, not all metabolites have been analysed simultaneously within the same tissue. The primary objective of this thesis was to determine full uterine prostanoid profiles in human non-pregnancy, pregnancy and parturition, to better understand these processes and find suitable tocolytic targets. In addition, ten cytokines in human cervico-vaginal fluid (CVF) were measured according to interval to labour to test their suitability as labour onset predictors, with a view to developing a test to determine women at risk of preterm labour. Prostanoid analysis was carried out in endometrium (n=9) and myometrium (n=15- 16) donated by non-pregnant women and lower segment myometrium obtained from pregnant women (before (n=14) and after labour onset (n=7)) by liquid chromatography coupled with electrospray ionisation mass spectrometry (LC/ESIMS/ MS). Cytokines produced by CVF collected from pregnant donors (20-41 weeks gestation, n=2-10) were investigated using Enzyme-Linked Immunosorbent Assay (ELISA) or Luminex®. Human endometrium produced greater concentrations of TXB2, PGE2 and PGF2α than myometrium in vitro (p<0.05). Fifteen prostanoids were detected in human myometrium. Production of 6-keto-PGF1α, PGE1 and PGF1α increased whilst 15- keto PGE2 and PGJ2 decreased at term pregnancy (37-41 weeks gestation) versus non-pregnancy (p<0.05). Myometrium from parturient donors synthesised TXB2 and PGE2 more abundantly than the non-labouring equivalent. Cytokine concentration was greatest in CVF sampled the week before labour, in particular Interleukin-6 (IL-6), Macrophage Inflammatory Protein-1α (MIP-1α) and Monocyte Chemotactic Protein-1 (MCP-1) (p<0.05). Endometrial TXB2, PGE2 and PGF2α could aid in proliferation of glandular epithelium prior to ovulation. Prostacyclin may facilitate prolongation of pregnancy to term and thromboxane could contribute to uterine stimulation during labour. Cervical dilation may be influenced by PGE2 in lower segment myometrium. MCP- 1, MIP-1α and IL-6 could mark a short interval to labour onset.
185

Synthesis of prostaglandins and novel N-oxyamide linked oligosaccharide and oligonucleotide mimetics / Synthèse de prostaglandines et de nouveaux mimes d’oligosaccharides et d'oligonucléotides liés par des liaisons N-oxy amide

Gong, Yanchun 30 August 2012 (has links)
Les prostaglandines (PG) jouent un rôle clé dans la régulation de la prolifération cellulaire, la différenciation et la régénération dans les systèmes gastro-intestinaux et cardio-vasculaires, et les réponses inflammatoires et immunitaires. Après un demi-siècle de développement, il a été démontré que PGs ont un large éventail de puissantes propriétés pharmacologiques sur l'inflammation, le glaucome, l'ostéoporose, le cancer, le diabète de type 2 et les maladies neuro-dégénératives. Les structures intéressantes et complexes de la PG et de leur disponibilité très limitée dans la nature ont suscité des chimistes organiques pour créer des méthodes de synthèse les plus élégantes afin de répondre à la recherche scientifique et les exigences pharmaceutiques. Dans cette thèse, nous avons réalisé la synthèse totale de la prostaglandine E2 (PGE2) en 24 étapes avec un rendement total de 1,33%, avec seulement 5 purifications chromatographiques pour l'ensemble du processus. Une synthèse efficace en one-pot des lactones de Corey a été mise au point à partir des dérivés chloro-cétoacide, en présence d'Oxone. Une méthode pratique pour la résolution racémique de l’acide 2-oxotricyclo [2.2.1.03,5]heptane-7-carboxylique avec haute valeur e.e. (> 99%) a également été développée. Les acides nucléiques et les glucides sont présents dans tous les systèmes vivants et jouent des rôles très importants en biologie comme l'expression des gènes et des processus de reconnaissance intracellulaires. Beaucoup d’efforts récents ont été consacrés au développement de mimes d'oligosaccharides et d’oligonucléotides synthétiques pour diverses applications biologiques, thérapeutiques et diagnostiques. Dans cette thèse, nous avons décrit la synthèse d'une nouvelle série d’oligosaccharides et d’oligonucléotide liés par des liaisons N-oxyamide. A partir de la diacétone D-glucose, les D-ribofuranoid glycoaminooxy acides ont été préparés comme une nouvelle famille de briques constitutives de sucre. Des homo-oligomères (de dimères à l'hexamère) ont été générés en tant que mimes d'oligosaccharides. Les nucléosides aminooxy acides ont été synthétisés pour la première fois, via la N-glycosylation des glycoaminooxy acides avec les cinq bases nucléiques. Le couplage entre les nucleosides aminooxy acides conduit aux dinucléosides liés par une liaison N-oxyamide. / Prostaglandins (PGs) play key roles in the regulation of cell proliferation, differentiation, and regeneration in gastrointestinal and cardiovascular systems, and a fundamental role in inflammatory and immune responses. After half century of development, PGs have been demonstrated to have a wide range of potent pharmacological properties on inflammation, glaucoma, osteoporosis, cancer, type 2 diabetes and neurodegenerative disorders. The interesting and complex structures of PGs and their very limited availability in nature have sparked the organic chemists to create more elegant synthesis methods to meet the scientific research and pharmaceutical demands. In this thesis, we have realized the total synthesis of prostaglandin E2 (PGE2) in 24 steps with a total yield of 1.33%, with only 5 chromatographic purifications for the whole process. An efficient one-pot synthesis of Corey lactones have been realized from the chloro-ketoacid derivatives in the presence of Oxone. A practical method for the resolution of racemic 2-oxotricyclo[2.2.1.03,5]heptane-7-carboxylic acid with high e.e. value (> 99%) has also been developed. Nucleic acids and carbohydrates are existing in all the living systems and play very important biological roles as gene expression and intracellular recognition processes. Much recent efforts have been devoted to the development of oligosaccharide mimetics and synthetic oligonucleotides for various biological, therapeutic and diagnostic applications. In this thesis, we have described the synthesis of a new series of N-oxyamide linked oligosaccharide and oligonucleotide mimetics. From the readily available diacetone D-glucose, D-ribofuranoid glycoaminooxy acid derivatives have been successfully prepared as a novel family of sugar building blocks. Homo-oligomers (dimer to hexamer) have been generated as oligosaccharide mimetics. Nucleoside aminooxy acids have been synthesized for the first time by N-glycosylation of sugar aminooxy acids with five common nucleic bases. Coupling reaction of nucleoside aminooxy acid derivatives furnished the desired N-oxy amide-linked dinucleosides.
186

Consequências da presença de periodontite induzida por ligadura em ratos sobre a resposta vaso motora in vitro de anéis de artéria mesentérica. / Consequences in the presence of ligature-induced periodontitis in rats on \"in vitro\" vasomotor response of mesenteric artery rings.

Jesus, Flávia Neto de 14 April 2014 (has links)
A destruição crônica do aparato periodontal devido a resposta inflamatória a bactérias, leva a um quadro clínico conhecido como doença periodontal. Patógenos periodontais podem ser translocados e liberados do sulco gengival à circulação sanguínea e apresentar efeitos periféricos. A bolsa periodontal também é importante reservatório de mediadores inflamatórios. A periodontite pode apresentar efeitos em órgãos distantes. Estudos passaram a documentar a relação entre doença periodontal e disfunção endotelial, reversível pelo tratamento odontológico. Nosso laboratório estudou a resposta vasomotora in vitro de anéis de aorta de ratos com periodontite, e os resultados preliminares mostram um aumento da resposta contrátil destes anéis à norepinefrina, quando comparado aos animais controle. O presente estudo objetiva avaliar a influência da periodontite induzida por ligadura em ratos sobre a resposta vasomotora in vitro de anéis de artéria mesentérica. Ainda, caracterizar os mediadores envolvidos, com ênfase nas enzimas ciclooxigenase e óxido nítrico sintase. / Chronic destruction of periodontal apparatus due to an intense inflammatory response to bacteria leads to a clinical condition known as periodontal disease. Periodontal pathogens can then translocate to the gingival sulcus and reach the bloodstream, and thus have peripheral effects. The periodontal pocket is also an important reservoir of inflammatory mediators. The periodontitis may have effects on organs distant. Studies have also documented the relationship between periodontal disease and endothelial dysfunction, which was reversible by dental treatment. In our laboratory we are studying the vasomotor response \"in vitro\" of aortic rings from rats with periodontitis, and the preliminary results show an increase in the contractile response of the rings to norepinephrine, when compared with control animals. This project aims to evaluate the influence of ligature-induced periodontitis in rats on the \"in vitro\" vascular reactivity of mesenteric artery vessels. Also, the characterization of the mediators involved, with emphasis on the enzyme of cyclooxygenase and nitric oxide synthase.
187

Avaliação das prostaglandinas e leucotrienos na infecção pulmonar induzida por Achromobacter xylosoxidans / Evaluation of prostaglandin and leukotrienes in lung infection induced by Achromobacter xylosoxidans.

Prado, Morgana Kelly Borges 24 February 2014 (has links)
Achromobacter xylosoxidans (A. xylosoxidans) é um bacilo gram negativo, aeróbio, móvel, não fermentador de glicose e oxidase positivo, que coloniza habitualmente o trato digestivo e auditivo de humanos. Este bacilo tem sido associado a infecções oportunistas graves, especialmente pneumonia, em indivíduos imunossuprimidos, que em geral, são de difícil controle devido principalmente a fatores de virulência, mecanismos de escape e mutirresistência a antibióticoterapia. Dentre as condições que predispõem o desenvolvimento de infecção pulmonar por A. xylosoxidans, o câncer, a fibrose cística (FC) e a doença pulmonar obstrutiva crônica (DPOC) são as mais comuns. Essas doenças apresentam produção aumentada de vários mediadores lipídicos, como LTB4 e PGE2. A PGE2 é um lipídeo imunossupressor atuante no sistema imune inato e adaptativo que regula, por exemplo, a liberação de citocinas e quimiocinas, a ativação de células T, além de inibir as funções efetoras dos macrófagos. O LTB4, por outro lado, está associado ao recrutamento de células para o foco infeccioso, a ativação dos mecanismos efetores dos macrófagos, e aumento de mediadores inflamatórios. Neste trabalho, nosso objetivo foi investigar se, esses mediadores são liberados durante a infecção pulmonar por A. xylosoxidans e o possível papel dos mesmos. Nossos resultados demonstram que os tratamentos com celecoxibe, inibidor da síntese de prostaglandinas (PGs), nas doses de 1mg/kg ou 5mg/kg, não alteram a sobrevida dos animais infectados com inóculo letal ou subletal de A. xylosoxidans. No entanto, o tratamento com MK886, um inibidor da produção de leucotrienos (LTs), resultou em aumento da mortalidade dos animais infectados com inóculos letal ou subletal, redução do recrutamento de neutrófilos no dia 1 após infecção, redução de IL-6 do dia 14 e aumento de TNF-, IL-1 e MIP-1 no dia 7, KC no dia 14 e PGE2, em todos os períodos estudados. Este tratamento também induziu no lavado broncoalveolar, a diminuição não significativa do extravasamento de proteínas no dia 1, mas aumento significativo no dia 3. Com base nesses dados, podemos sugerimos que o tratamento com MK886 aumenta a mortalidade dos animais, devido ao aumento da permeabilidade vascular, com consequente edema, que leva os animais a insuficiência respiratória. Outros experimentos serão realizados para determinar o papel das prostaglandinas (PGs) e/ou metabolitos do ácido araquidônico neste fenômeno. / Achromobacter xylosoxidans (A. xylosoxidans) is a gram negative bacilli, aerobic, mobile, glucose non fermenter and oxidase positive, which normally colonizes the digestive and auditory tract of humans. This bacillus has been associated with severe opportunistic infections, especially pneumonia, in immunocompromised individuals, which are generally difficult to control mainly due to virulence factors, mechanisms and exhaust multidrug resistance to antibiotic therapy. Among the conditions that predispose the development of pulmonary infection by A. xylosoxidans, cancer, cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD) are the most common. These diseases have increased production of various lipid mediators, such as LTB4 and PGE2. PGE2 is an immunosuppressive lipid active in the innate and adaptive immune system that regulates, for example, the release of cytokines and chemokines, activation of T cells and inhibits the effector functions of macrophages. LTB4, on the other hand, is associated with the recruitment of cells to the infection, and the activation of effector mechanisms of macrophages, and increased production of inflammatory mediators. In this study, our aim was to investigate whether these mediators are released during pulmonary infection by A. xylosoxidans and the possible role of the same. Our results demonstrate that treatment with celecoxib, prostaglandin synthesis inhibitor (PGs), at doses of 1mg/kg or 5mg/kg not alter the survival of animals infected with lethal or sublethal inoculum of A. xylosoxidans. However, treatment with MK886, an inhibitor of the production of leukotrienes (LTs) resulted in an increased mortality of the animals infected with lethal or sublethal inoculum, reduce the recruitment of neutrophils on day 1 after infection, reduction in IL-6 day 14 and increased TNF-, IL-1 and MIP-1 at day 7, KC in day 14 and PGE2 in all periods. This treatment also induced in the bronchoalveolar lavage, no significant decrease protein extravasation in the day 1, but significantly increased on day 3. Based on these data, we suggest that treatment with MK886 increases the mortality of animals due to increased vascular permeability, with consequent edema, which leads the animals to respiratory failure. Other experiments will be conducted to determine the role of prostaglandins (PGs) and/or metabolites of arachidonic acid in this phenomenon.
188

Análise do papel das ciclooxigenases 1 e 2 na migração da linhagem celular de glioma humano U251-MG. / The role of cyclooxygenases 1 and 2 in the migration of human glioma cell line U251MG.

Stevanatto, Pollyana Bulgarelli 08 March 2013 (has links)
O glioblastoma multiforme (GBM) é um dos gliomas mais comuns, classificado como um glioma de grau IV (Organização Mundial da Saúde - OMS) e notoriamente difícil de ser tratado. O tratamento recomendado consiste na ressecção cirúrgica seguida de radio e quimioterapia, e a sobrevida média dos pacientes é de apenas 12 meses após o diagnóstico. Portanto, novas terapias que focam a redução do volume do tumor e o aumento da morte das células tumorais são urgentemente necessárias. Estudos pré-clínicos sugerem que a inibição de COX-1 e 2 com Anti-inflamatórios não esteroidais (AINEs), como o Ibuprofeno (IBP), inibiram significantemente a proliferação e a migração celular em diferentes tumores. Assim, o presente estudo teve como objetivo avaliar in vitro o efeito da inibição de COX-1 e COX-2 através do tratamento com IBP, e também com inibidores específicos como SC-560 e NS-398 respectivamente, na migração e na proliferação da linhagem celular de glioma humano U251-MG. O presente estudo demonstrou através de diversos ensaios que a inibição de COX-1 e COX-2 através do IBP, do SC-560 e do NS-398 inibiu significativamente a migração e a proliferação celular da linhagem celular U251-MG. Dessa maneira, concluímos que a PGE2 está envolvida na migração e proliferação celular das células desta linhagem celular. / Glioblastoma Multiforme (GBM) is the most common glioma, classified as grade IV (World Health Organization WHO) and notoriously difficult to treat. The recommended treatment consists of surgery followed by radiotherapy and chemotherapy, and the median survival is ten to twelve months. Preclinical studies suggest that inhibiton of cyclooxygenase-2 by treatment with non-steroidal anti-inflammatory drugs, such as ibuprofen, significantly blocked the proliferation of different tumors including gliomas. Thus this study aimed to evaluate the migration of glioma cell line U251-MG after inhibition of cyclooxygenases 1 and 2 by treatment with ibuprofen (IBP), and specifics inhibitors such as SC-560 for COX-1 and NS-398 for COX-2. The present study demonstrated by various assays where inhibition of COX-1 and COX-2 by IBP, SC-560 and NS-398, significantly inhibited migration and cell proliferation of U251-MG cell line. Thus, we conclude that PGE2 is involved in this cell line migration and cell proliferation.
189

Papel dos leucotrienos na proteção conferida pela imunização heteróloga BCG/DNA-HSP65 contra tuberculose / Role of leukotrienes in immune protection conferred by the heterologous immunization BCG/DNA-HSP65 against tuberculosis

Franco, Luís Henrique 12 August 2009 (has links)
A tuberculose é responsável por mais de 2 milhões de mortes ao ano. A imunidade protetora contra a tuberculose está relacionada com a ativação de linfócitos CD4+ e CD8+ produtores de IFN-g, citocina que potencializa os mecanismos microbicidas dos macrófagos para eliminação dos bacilos. Nos últimos anos, o leucotrieno B4 (LTB4) destacou-se como mediador lipídico que participa da imunidade protetora contra diversas infecções, incluindo a tuberculose. Dessa forma, o objetivo desse estudo foi avaliar o papel dos leucotrienos na proteção induzida pela imunização homóloga com DNA-HSP65 ou heteróloga com BCG/DNA-HSP65. Para isso, inicialmente, nós confirmamos a participação dos leucotrienos no controle da infecção por M. tuberculosis ao mostrar que animais C57BL/6, que controlam a replicação dos bacilos, secretam mais LTB4; e ao bloquear a síntese de leucotrienos com a droga MK-886, estes animais ficaram suscetíveis à infecção. Em seguida, nós passamos a avaliar se os leucotrienos participavam da proteção conferida pela imunização homóloga com DNA-HSP65 ou heteróloga (prime-boost) com BCG/DNA-HSP65. Nossos resultados mostraram que animais deficientes para a síntese de LT (5-LO KO) infectados foram mais suscetíveis à infecção em relação aos animais WT. A maior suscetibilidade dos animais 5-LO KO foi associada à redução na secreção de IFN-g, nitrito e IL-17, aumento na secreção de PGE2, defeitos no recrutamento de células inflamatórias e aumento no influxo de células Foxp3+ para os pulmões. A imunização homóloga perdeu completamente seu efeito protetor na ausência de leucotrienos, enquanto a imunização heteróloga induziu proteção parcial. Animais 5-LO KO imunizados pelo esquema prime-boost secretaram concentrações mais elevadas de IL-17 e tiveram menor influxo de células Foxp3+ para os pulmões quando comparados aos animais 5-LO KO não imunizados e infectados. A inibição da síntese de prostaglandinas durante o protocolo de imunização pela estratégia prime-boost reduziu a capacidade protetora da vacina tanto em animais WT como nos 5-LO KO, sugerindo que as prostaglandinas podem desempenhar papel no processo de imunização. Em conjunto, nossos resultados reforçam a importância dos leucotrienos na imunidade protetora contra tuberculose, sugerindo sua atuação indireta, uma vez que, além de contribuírem para síntese de IFN-g e nitrito, também parecem colaborar na síntese de IL-17. / Tuberculosis is responsible for more than 2 millions of death for year. The immune response against tuberculosis is related to activation of IFN-g-producing CD4+ and CD8+ cells. IFN-g increases the microbicidal mechanisms of macrophages to kill intracellular bacilli. Recently, the lipid mediator leukotriene B4 (LTB4) has been related to protection against several diseases, including tuberculosis. In this sense, the aim of this study was to evaluate the role of leukotrienes in the protection induced by homologous immunization with DNA-HSP65 or heterologous with BCG/DNA-HSP65 (prime-boost). Firstly, we confirmed the role of leukotrienes to control the replication of M. tuberculosis when we showed that C57BL/6 mice, which are able to contain bacilli growth, secreted high levels of LTB4; and when we blocked leukotrienes synthesis by treatment with MK-886, C57BL/6 mice became more susceptible to infection. Then, we evaluated the role of leukotrienes in the protection induced by homologous or heterologous (prime-boost) immunization. Our data showed that animals deficient in leukotrienes synthesis (5-LO KO) infected with M. tuberculosis were more susceptible to infection than WT mice. The higher susceptibility of 5-LO KO was related to the decreasing of IFN-g, nitrite and IL-17 production, increasing of PGE2 secretion, defective recruitment of inflammatory cells and increased influx of Foxp3+ cells to the lungs. Homologous immunization has lost completely its protector effect in the absence of leukotrienes, while heterologous immunization induced only partial protection. Prime-boost-immunized 5-LO KO mice secreted higher levels of IL-17 and had lower influx of Foxp3+ cells to the lungs, when compared to non-immunized infected 5-LO KO. The abrogation of the synthesis of prostaglandins during the immunization by prime-boost reduced the protector effect of the vaccine either in WT and 5-LO KO mice, suggesting that prostaglandins may be important to the process of immunization. Together, our data reinforce the key role of leukotrines in immune response against tuberculosis, suggesting that these lipid mediators may act indirectly to induce IFN-g, nitrite and IL-17 synthesis.
190

Alterações conjuntivais induzidas por análogos das prostaglandinas e maleato de timolol: estudo histomorfométrico / Conjunctival changes induced by prostaglandin analogues and timolol maleate: a histomorphometric study

Giacometti, Heloisa Helena Abil Russ 17 September 2007 (has links)
O objetivo deste estudo foi comparar alterações histológicas induzidas por análogos de prostaglandinas e maleato de timolol na conjuntiva de coelhos. Cinqüenta coelhas da raça Nova Zelândia com idade e peso semelhantes foram divididos em cinco grupos de dez animais. Os olhos esquerdos foram tratados com uma gota diária de bimatoprosta 0,03%, travoprosta 0,004%, latanoprosta 0,005%, maleato de timolol 0,5% ou lágrimas artificiais contendo cloreto de benzalcônio (CBA) durante 30 dias. Os olhos contra-laterais serviram como controles. Realizaram-se biópsias na conjuntiva limbar superior com dimensões de 5 mm x 5 mm no oitavo e trigésimo dias em cinco coelhos de cada grupo. A conjuntiva foi imediatamente fixada com formaldeído a 10% por 24 horas, seguido de coloração por Hematoxilina-Eosina (HE) e Ácido Periódico de Shiff (PAS) e avaliação qualitativa por microscopia óptica. A avaliação histo-morfométrica quantitativa foi realizada usando o programa Image Pro-Plus 4.5. Os parâmetros avaliados foram: infiltrado inflamatório, espessura epitelial, número de células caliciformes, diâmetro e número de vasos sanguíneos. Observou-se leve infiltrado inflamatório focal no tecido conectivo subepitelial nos olhos controle e do grupo CBA, que consistia de aglomerados de linfócitos e raros neutrófilos. Todos os demais grupos exibiram no oitavo e trigésimo dias de tratamento infiltrado inflamatório moderado, composto por linfócitos e neutrófilos, que foi mais denso no grupo tratado com maleato de timolol do que nos grupos dos análogos de prostaglandinas. No trigésimo dia, o grupo que recebeu timolol mostrou aumento da densidade subepitelial de colágeno e aumento estatisticamente significante da espessura epitelial (P=0,004), que não foram observados nos demais grupos. Observou-se um aumento estatisticamente significante do número de vasos no grupo tratado com timolol (P=0,001). O diâmetro vascular no grupo que recebeu travoprosta apresentou aumento estatisticamente significante no oitavo dia de tratamento (P=0,008) e redução no 30º dia (P=0,035). A densidade de células caliciformes aumentou significativamente no grupo que recebeu travoprosta no oitavo dia (P=0,001) e no 30º dia nos grupos tratados com bimatoprosta (P=0,002) e latanoprosta (P=0,009). Conclui-se que, na conjuntiva de coelhos, o número de células caliciformes aumenta com o uso de análogos das prostaglandinas. O estudo sugere que essas drogas, entretanto, induzem menos alterações que o maleato de timolol na conjuntiva de coelhos / The purpose of this study was to compare histological changes induced by prostaglandin analogues and timolol maleate in the rabbit conjunctiva. Fifty New Zealand female rabbits with similar age and weight were divided in five groups of 10 animals. The left eyes were treated with one daily drop of bimatoprost 0,03%, travoprost 0,004%, latanoprost 0,005%, timolol maleate 0,5% or artificial tears containing benzalkonium chloride (BAC) for 30 days. The fellow eyes served as controls. Limbal superior conjunctival biopsies of 5 mm x 5 mm were performed at the 8th and 30th day in five rabbits of each group each time. The conjunctiva was immediately fixed with 10% formaldehyde for 24 hours, followed by Hematoxiline-Eosine (HE) and Periodic Acid Shiff (PAS) staining and optical qualitative microscopic evaluation. Morphohistometric quantitative analyses were conducted using the Image Pro-Plus 4.5 software. The evaluated parameters were: inflammatory infiltrate, epithelial thickness, number of goblet cells, diameter and number of blood vessels. A low level infiltration, consisting of localized clusters of lymphocytes and rare neutrophils, was observed in the subepithelial connective tissue of the control eyes and in the BAC group. At the 8th and 30th day post treatment, all other groups exhibited a diffuse inflammatory infiltrate, composed by lymphocytes and neutrophils, which was denser in the timolol group than in the prostaglandin analogue groups. At the 30th day, the timolol group also showed an increased subepithelial collagen density and a significant increase in epithelial thickness (P=0.004), which was not present in the other groups. A significant increase (P =0.001) in the number of blood vessels was observed in the group treated with timolol. An initial increase in the vascular diameter was observed at the 8th day in the travoprost group (P=0,008) although a significant reduction was observed at the 30th day (P =0,035). The goblet cell density was significantly increased at the 8th day in the group treated with travoprost (P =0.001) and at the 30th day in those treated with bimatoprost (P =0.002) and latanoprost (P =0.009). We conclude that an increase in the number of goblet cell was initially observed with the use of all prostaglandin analogues. This study suggests that these drugs, however, induce fewer changes than timolol maleate in the rabbit conjunctiva

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