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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.
151

Estudo in vitro do efeito da prostaglandina E2 na migração das células U87MG e U251MG, evidenciando a matriz extracelular e as moléculas de adesão. / In vitro study of the effect of prostaglandin E2 on cell migration of U87MG and U251MG, highlighting the extracellular matrix and adhesion molecules.

Fábio Feitoza 07 March 2014 (has links)
O glioblastoma multiforme (GBM) é uma neoplasia do sistema nervoso central (SNC), caracterizada por uma elevada capacidade proliferativa e migratória. O desenvolvimento do tumor provoca uma remodelação da matriz extracelular (MEC) que facilita a migração tumoral. Eicosanóides são moléculas lipídicas importantes na carcinogênese e a sua síntese está correlacionada com o grau de desenvolvimento do tumor. As prostaglandinas são eicosanóides envolvidas na estimulação da angiogênese, na adesão celular e proliferação celular. Este estudo tem por objetivo avaliar in vitro o efeito da PGE2 na expressão moléculas da MEC e das moléculas de adesão envolvidas na migração, em células U87MG e U251MG. As células U251MG e U87MG foram tratadas com PGE2 (10µM) e Ibuprofeno (25µM), por um período 48hs. As proteínas da MEC foram analisadas por RT-qPCR após o tratamento. Foram realizadas reações de imunohistoquímica para as moléculas da MEC. As alterações foram encontradas na expressão de laminina, fibronectina, colágeno tipo IV e as integrinas αv , α3 e α5 para células U87MG . Observamos imunomarcação nas linhas celulares para colágeno tipo IV, laminina e fibronectina. Concluímos que o tratamento com IBU e PGE2, afeta a expressão gênica de moléculas de MEC. / Glioblastoma Multiforme (GBM) is a neoplasm of the central nervous system (CNS), characterized by a high proliferative and migratory capacity. Tumor development leads to extracellular matrix (ECM) remodeling and facilitating the migration of these cells. Eicosanoids are important lipid molecules in carcinogenesis, and their synthesis often correlates with the degree of tumor development. Prostaglandins are eicosanoids involved in the stimulation of angiogenesis, cell adhesion and cell proliferation. This study is aimed to evaluate the expression of several ECM molecules involved in migration after altering the concentration of prostaglandins, using human glioma cell lines as an in vitro model. The cell lines U87MG and U251MG were treated with PGE2 (10µM) and Ibuprofen (25µM), for a predetermined period of 48hs. Proteins involved in extracellular matrix were analyzed by RT-qPCR after treatment in vitro. Immunohistochemical reactions were also performed for the ECM molecules. Changes were found in the expression of laminin, fibronectin, type IV collagen and αv, α3 and α5 integrins in cells U87MG. We observed immunostaining in cell lines to type IV collagen, laminin and fibronectin. In conclusion, Ibuprofen and PGE2, affects gene expression of ECM molecules.
152

Endothelial HSPA12B Exerts Protection Against Sepsis-Induced Severe Cardiomyopathy via Suppression of Adhesion Molecule Expression by miR-126

Zhang, Xia, Wang, Xiaohui, Fan, Min, Tu, Fei, Yang, Kun, Ha, Tuanzhu, Liu, Li, Kalbfleisch, John, Williams, David, Li, Chuanfu 29 April 2020 (has links)
Heat shock protein A12B (HSPA12B) is predominately expressed in endothelial cells (ECs) and has been reported to protect against cardiac dysfunction from endotoxemia or myocardial infarction. This study investigated the mechanisms by which endothelial HSPA12B protects polymicrobial sepsis–induced cardiomyopathy. Wild-type (WT) and endothelial HSPA12B knockout (HSPA12B–/–) mice were subjected to polymicrobial sepsis induced by cecal ligation and puncture (CLP). Cecal ligation and puncture sepsis accelerated mortality and caused severe cardiac dysfunction in HSPA12B–/– mice compared with WT septic mice. The levels of adhesion molecules and the infiltrated immune cells in the myocardium of HSPA12B–/– septic mice were markedly greater than in WT septic mice. The levels of microRNA-126 (miR-126), which targets adhesion molecules, in serum exosomes from HSPA12B–/– septic mice were significantly lower than in WT septic mice. Transfection of ECs with adenovirus expressing HSPA12B significantly increased miR-126 levels. Increased miR-126 levels in ECs prevented LPS-stimulated expression of adhesion molecules. In vivo delivery of miR-126 carried by exosomes into the myocardium of HSPA12B–/– mice significantly attenuated CLP sepsis increased levels of adhesion molecules, and improved CLP sepsis–induced cardiac dysfunction. The data suggest that HSPA12B protects against sepsis-induced severe cardiomyopathy via regulating miR-126 expression which targets adhesion molecules, thus decreasing the accumulation of immune cells in the myocardium.
153

Isolation and characterization of SOS5 in a novel screen for plasma membrane to cell wall adhesion genes in Arabidopsis thaliana

McFarlane, Heather Elizabeth, 1983- January 2008 (has links)
No description available.
154

Mechanisms responsible for homocysteine mediated damage to human endothelial cells : the role of oxidative stress in atherogenesis.

Alkhoury, Kenan January 2009 (has links)
Homocysteine (Hcy) has been identified as a primary risk factor for atherosclerosis as it induces endothelial cell (EC) activation/dysfunction and thus potentially initiating atherosclerotic plaque formation. There is accumulating evidence indicating a key role for oxidative stress in mediating Hcy atherogenic effects. The aim of this study was to evaluate the effects of chronic treatment with Hcy on EC activation and to explore the role of oxidative stress in these effects. Human umbilical vein endothelial cells (HUVEC) were cultured and treated chronically with DL-Hcy for 5-9 days. An in vitro flow system was also used to characterize the different types of interactions between DL-Hcy-treated HUVEC and neutrophils under physiological flow conditions. EC activation was studied by characterizing the activation of the JNK pathway and the up-regulation of different cell adhesion molecules (CAM) and cytokines, using different techniques including western blot, immunohistochemical staining, enzyme-linked immunosorbent assay and polymerase chain reaction. The role of oxidative stress was investigated by measuring the production of ROS and evaluating the efficiency of antioxidants. Furthermore, the role of nitric oxide and nitric oxide synthase in modulating Hcy effects was investigated. Chronic treatment with DL-Hcy did not kill the EC however, it inhibited cell proliferation. Furthermore, this treatment induced EC activation/dysfunction which was characterized by sustained activation of the JNK pathway, which in turn mediated up-regulation of E-selectin, ICAM-1 and to lesser extent P-selectin. Furthermore, DL-Hcy induced production of IL-8 protein. These CAM and chemokines collectively mediated different interactions between DL-Hcy-treated HUVEC and neutrophils under flow conditions including tethering, rolling, adherence and transmigration. DL-Hcy was also shown to induce significant ROS generation which mediated activation of the JNK pathway. Antioxidants restored DL-Hcy-induced interactions under flow to the basal level. DL-Hcy was shown to induce eNOS uncoupling which mediated, at least in part, the DL-Hcy-induced ROS production. Furthermore, short term treatment with NO inhibited DL-Hcy-induced HUVEC:neutrophil interactions in a cGMP-independent manner. In summary, this research showed that DL-Hcy has several proatherogenic effects, mediated at least in part by the JNK pathway, and induces EC activation/dysfunction priming for atherosclerosis initiation. The data supports that oxidative stress mediates the majority of Hcy atherosclerotic effects. Antioxidants tested, JNK inhibitors and NO showed promising results in reversing all DL-Hcy effects and restoring EC normal status. ¿
155

The Influence of Stored Product Mites on the Function of Skin Microvascular Endothelial Cells

Curp, Jennifer Graff 28 April 2010 (has links)
No description available.
156

Effect of transforming growth factor-β on up/down regulation of integrin-β1 in primary chondrocyte culture

Khaghani, Seyed A., Sefat, Farshid, Youseffi, Mansour, Rehman, R., Soon, Chin Fhong, Akbarova, G. January 2016 (has links)
yes / Regeneration of a damaged or non-functioning tissue requires adhesion of cells to their extracellular matrix (ECM). Thus the investigation of the level of synthesised cell adhesion molecules (CAMs) in cell culture systems play major roles in cell and tissue engineering. Adhesion of chondrocyte to a collagen type-II rich matrix, is dependent on cell adhesion molecules (CAMs) and integrins and cells adhere to ECM through integrins.
157

Factors influencing nerve growth in situ and in vitro /

Jerregård, Helena, January 2001 (has links) (PDF)
Diss. (sammanfattning) Linköping : Univ., 2001. / Härtill 4 uppsatser.
158

Mechanisms responsible for homocysteine mediated damage to human endothelial cells : the role of oxidative stress in atherogenesis

Alkhoury, Kenan January 2009 (has links)
Homocysteine (Hcy) has been identified as a primary risk factor for atherosclerosis as it induces endothelial cell (EC) activation/dysfunction and thus potentially initiating atherosclerotic plaque formation. There is accumulating evidence indicating a key role for oxidative stress in mediating Hcy atherogenic effects. The aim of this study was to evaluate the effects of chronic treatment with Hcy on EC activation and to explore the role of oxidative stress in these effects. Human umbilical vein endothelial cells (HUVEC) were cultured and treated chronically with DL-Hcy for 5-9 days. An in vitro flow system was also used to characterize the different types of interactions between DL-Hcy-treated HUVEC and neutrophils under physiological flow conditions. EC activation was studied by characterizing the activation of the JNK pathway and the up-regulation of different cell adhesion molecules (CAM) and cytokines, using different techniques including western blot, immunohistochemical staining, enzyme-linked immunosorbent assay and polymerase chain reaction. The role of oxidative stress was investigated by measuring the production of ROS and evaluating the efficiency of antioxidants. Furthermore, the role of nitric oxide and nitric oxide synthase in modulating Hcy effects was investigated. Chronic treatment with DL-Hcy did not kill the EC however, it inhibited cell proliferation. Furthermore, this treatment induced EC activation/dysfunction which was characterized by sustained activation of the JNK pathway, which in turn mediated up-regulation of E-selectin, ICAM-1 and to lesser extent P-selectin. Furthermore, DL-Hcy induced production of IL-8 protein. These CAM and chemokines collectively mediated different interactions between DL-Hcy-treated HUVEC and neutrophils under flow conditions including tethering, rolling, adherence and transmigration. DL-Hcy was also shown to induce significant ROS generation which mediated activation of the JNK pathway. Antioxidants restored DL-Hcy-induced interactions under flow to the basal level. DL-Hcy was shown to induce eNOS uncoupling which mediated, at least in part, the DL-Hcy-induced ROS production. Furthermore, short term treatment with NO inhibited DL-Hcy-induced HUVEC:neutrophil interactions in a cGMP-independent manner. In summary, this research showed that DL-Hcy has several proatherogenic effects, mediated at least in part by the JNK pathway, and induces EC activation/dysfunction priming for atherosclerosis initiation. The data supports that oxidative stress mediates the majority of Hcy atherosclerotic effects. Antioxidants tested, JNK inhibitors and NO showed promising results in reversing all DL-Hcy effects and restoring EC normal status.
159

Estudo de moléculas de adesão no câncer de mama bilateral / Analyse of adhesion molecules in bilateral breast câncer

Iyeyasu, Hirofumi 26 January 2011 (has links)
Carcinoma da mama com apresentação bilateral é uma doença pouco avaliada na literatura, com raros trabalhos científicos que comparam os aspectos moleculares de ambos os tumores. No presente estudo, analisamos os tumores de 45 pacientes portadoras de carcinoma ductal invasivo bilateral em relação às expressões de claudinas-4 e 7, de E-caderina e de -catenina por meio de imunoistoquímica em TMA. Além desses marcadores, analisamos o estado dos receptores de estrógeno e de progesterona, bem como diversas características histopatológicas (grau histológico, nuclear, mitose, infiltrado, desmoplasia e necrose). A amostra foi caracterizado por média de idade de 52,4 anos e os tumores foram divididos em mama primário (MP) e mama secundário (MS). Não houve diferenças entre os dois grupos (MP e MS) nos marcadores testados, sendo que a expressão foi coincidente nas seguintes proporções: claudina-4 (83,8%, p=0,61), claudina-7 (82,2%, p=0,29), E-caderina (81%, p=0,48), -catenina (89,7%, p=0,48), receptor de estrogeno (66%, p=0.75) e receptor de progesterona (55%, p=0.99). Em relação aos aspectos morfológicos, grau histológico (SBR) II, infiltrado inflamatório discreto, necrose, desmoplasia moderada e índice mitótico (<10fm/10cga) foram coincidentes em 57,8%, 60%, 55,6%, 63,6% e 55,6%, respectivamente. Os presentes resultados nos permitem inferir que os tumores de apresentação bilateral são, em sua maioria, similares do ponto de vista morfológico e da expressão dos marcadores testados / Forty-five patients with invasive ductal carcinoma were evaluated for the expression of claudin-4, claudin-7, E-cadherin, and -catenin through tissue microarray (TMA) and immunohistochemistry (IHC) analysis. Besides these markers, estrogen (ER) and progesterone receptor (PR) status was analyzed, in addition to histopathologic characteristics, i.e., histologic grade, nuclear, mitoses, infiltrate, desmoplasia, and necrosis. Tumors were divided into primary breast (PB) and secondary breast (SB). The expression of claudin-4 and -7 was coincident in PB and SB in 83.78% and 82.22% respectively. The expression of -catenin and E-cadherin in PB and SB was coincident in 89.74% and 80.95% respectively. Estrogen receptor status was (+) in both breasts in 66%, while progesterone receptor status (+) was in 55%. The histological grade using the Nottingham-modified Scarff-Bloom-Richardson grading system (MSBR) showed mild infiltrate, necrosis (+), moderate desmoplasia and mitotic index (<10) was coincident in 57.77%, 60.00%, 55.55%, 63.63% and 55.55% respectively. The degree of agreement showed claudin-4 (p=0.61), claudin-7 (p=0.29), E-cadherin (p=0.48), and -catenin (p=0.48). The expression of claudin-4 and -7, E-cadherin and -catenin present a strong agreement between tumors, showing that bilateral tumors are not different. Histopathologic characteristics showed a lesser agreement between tumors
160

Efeitos da hidroquinona sobre atividades funcionais da célula endotelial e de neutrófilos / Effect of hydroquinone in the functional activity of endothelial cells and neutrophils

Pinedo, Fernanda Júdice 11 August 2009 (has links)
A hidroquinona (HQ) é um composto fenólico obtido a partir da metabolização endógena do benzeno, está presente no cigarro, medicamentos, reveladores fotográficos, alimentos e plantas medicinais. Temos demonstrado que a intoxicação experimental de ratos à HQ compromete a migração de leucócitos para o pulmão na vigência de resposta inflamatória alérgica ou inespecífica. O presente trabalho visou avaliar os efeitos da HQ sobre atividades da célula endotelial e de neutrófilos envolvidas na inflamação. Culturas primárias de células endoteliais da rede microcirculatória obtidas do músculo cremaster de ratos Wistar, machos, foram tratadas com HQ (10 ou 100 µM, 2 horas) e posteriormente incubadas ou não com LPS de E. coli (LPS; 2 µg/mL). Neutrófilos obtidos da cavidade peritoneal de ratos Wistar, 4 horas após a injeção local de glicogênio de ostra (10 mL, 1%) , foram tratados com HQ (5 ou 10 µM, 1 hora) e, em seguida, foram incubados ou não com LPS (5 µg/mL). Células controles receberam volumes equivalentes dos veículos da HQ e do LPS. Os dados obtidos mostram que o tratamento com a HQ não induziu necrose ou apoptose em ambos os tipos celulares; reduziu a produção de NO pela célula endotelial e por neutrófilos, por bloqueio das atividades das óxido nítrico sintases; reduziu a expressão gênica e protéica de TNF-&#945;, IL-6 e IL-1&#946; induzida pelo LPS em neutrófilos, possivelmente decorrente de redução da translocação nuclear do NF&#954;B; por outro lado aumentou a expressão gênica e protéica basal de TNF-&#945;, IL-1&#946;, ICAM-1, PECAM-1 e VCAM-1, bem como a translocação nuclear do NF-&#954;B; reduziu a atividade fagocítica e microbicida de neutrófilos frente a Candida albicans; não afetou a expressão gênica da CYP2E1 em ambos os tipos celulares, mas aumentou a expressão gênica de MPO em neutrófilos. Em conjunto, os dados permitem concluir que a HQ atua diferentemente nos dois tipos de células estudadas, ativando e inibindo propriedades inflamatórias na célula endotelial e nos neutrófilos, respectivamente. É possível as ações sobre os neutrófilos possam contribuir, pelo menos em parte, pela redução da migração celular durante a resposta inflamatória observada após exposição in vivo à HQ. / Hydroquinone (HQ) is a fenolic compound obtained after benzene metabolism, it is a component of cigarette, medicines, photographic developer, and it is also finding in some foods and medicinal herbs. Our research group has been shown that rats in vivo exposed to HQ present impaired leukocyte migration into lung during allergic or non-specific inflammation. In the present study, we investigate the effects of HQ on functional activities of neutrophils and endothelial cells (EC) involved in inflammation. Primary cultured EC was obtained from microcirculatory network of male Wistar rats, and treated with HQ (10 or 100 µM, two hours). After the treatments, EC was incubated in presence or absence of lipopolissacharide of E. coli (LPS; 2 µg/mL). Peritoneal neutrophils obtained four hours after local injection of oyster glycogen (10 mL, 1%) were incubated with HQ (5 or 10 µM, one hour) and in sequence it was incubated in presence or absence of LPS (5 µg/mL) .Control cells were cultured with equivalent volumes of HQ and LPS vehicle. Results obtained showed that treatment with HQ did not induce apoptosis or necrosis in both types of cells; impaired NO production by endothelial cells and neutrophils dependent on blockade of Ca+2-dependent and independent NOS activity; decreased gene and protein expression of TNF-&#945;, IL-6 and IL-1&#946; in neutrophils induced by LPS, possibly due to reduced nuclear translocation of the NF-&#954;B. On the other hand, HQ treatment enhanced basal protein and gene expression of TNF-&#945;, IL-1&#946; , ICAM-1, PECAM-1 and VCAM-1 and the nuclear translocation of NF-&#954;B; impaired Candida albicans phagocytic and killing indexes; did not affect the gene expression of CYP2E1 in both types of cell, but increased the gene expression of MPO in neutrophils. Taken together, results obtained show that HQ acts differently in the two types of cells studied, activating and inhibiting inflammatory properties in endothelial cells and neutrophils, respectively. Actions on neutrophils may contribute, at least in part, on the reduced leukocyte recruitment during in vivo HQ exposure.

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