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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.
161

Role of Inducible Nitric Oxide Synthase and Melatonin in Regulation of β-cell Sensitivity to Cytokines

Andersson, Annika K. January 2003 (has links)
<p>The mechanisms of β-cell destruction leading to type 1 diabetes are complex and not yet fully understood, but infiltration of the islets of Langerhans by autoreactive immune cells is believed to be important. Activated macrophages and T-cells may then secrete cytokines and free radicals, which could selectively damage the β-cells. Among the cytokines, IL-1β, IFN-γ and TNF-α can induce expression of inducible nitric synthase (iNOS) and cyclooxygenase-2. Subsequent nitric oxide (NO) and prostaglandin E<sub>2</sub> (PGE<sub>2</sub>) formation may impair islet function.</p><p>In the present study, the ability of melatonin (an antioxidative and immunoregulatory hormone) to protect against β-cell damage induced by streptozotocin (STZ; a diabetogenic and free radical generating substance) or IL-1β exposure was examined. <i>In vitro</i>, melatonin counteracted STZ- but not IL-1β-induced islet suppression, indicating that the protective effect of melatonin is related to interference with free radical generation and DNA damage, rather than NO synthesis. <i>In vivo</i>, non-immune mediated diabetes induced by a single dose of STZ was prevented by melatonin.</p><p>Furthermore, the effects of proinflammatory cytokines were examined in islets obtained from mice with a targeted deletion of the iNOS gene (iNOS -/- mice) and wild-type controls. The <i>in vitro</i> data obtained show that exposure to IL-1β or (IL-1β + IFN-γ) induce disturbances in the insulin secretory pathway, which were independent of NO or PGE<sub>2</sub> production and cell death. Initially after addition, in particular IL-1β seems to be stimulatory for the insulin secretory machinery of iNOS –/- islets, whereas IL-1β acts inhibitory after a prolonged period. Separate experiments suggest that the stimulatory effect of IL-1β involves an increased gene expression of phospholipase D1a/b. In addition, the formation of new insulin molecules appears to be affected, since IL-1β and (IL-1β + IFN-γ) suppressed mRNA expression of both insulin convertase enzymes and insulin itself.</p>
162

Role of Inducible Nitric Oxide Synthase and Melatonin in Regulation of β-cell Sensitivity to Cytokines

Andersson, Annika K. January 2003 (has links)
The mechanisms of β-cell destruction leading to type 1 diabetes are complex and not yet fully understood, but infiltration of the islets of Langerhans by autoreactive immune cells is believed to be important. Activated macrophages and T-cells may then secrete cytokines and free radicals, which could selectively damage the β-cells. Among the cytokines, IL-1β, IFN-γ and TNF-α can induce expression of inducible nitric synthase (iNOS) and cyclooxygenase-2. Subsequent nitric oxide (NO) and prostaglandin E2 (PGE2) formation may impair islet function. In the present study, the ability of melatonin (an antioxidative and immunoregulatory hormone) to protect against β-cell damage induced by streptozotocin (STZ; a diabetogenic and free radical generating substance) or IL-1β exposure was examined. In vitro, melatonin counteracted STZ- but not IL-1β-induced islet suppression, indicating that the protective effect of melatonin is related to interference with free radical generation and DNA damage, rather than NO synthesis. In vivo, non-immune mediated diabetes induced by a single dose of STZ was prevented by melatonin. Furthermore, the effects of proinflammatory cytokines were examined in islets obtained from mice with a targeted deletion of the iNOS gene (iNOS -/- mice) and wild-type controls. The in vitro data obtained show that exposure to IL-1β or (IL-1β + IFN-γ) induce disturbances in the insulin secretory pathway, which were independent of NO or PGE2 production and cell death. Initially after addition, in particular IL-1β seems to be stimulatory for the insulin secretory machinery of iNOS –/- islets, whereas IL-1β acts inhibitory after a prolonged period. Separate experiments suggest that the stimulatory effect of IL-1β involves an increased gene expression of phospholipase D1a/b. In addition, the formation of new insulin molecules appears to be affected, since IL-1β and (IL-1β + IFN-γ) suppressed mRNA expression of both insulin convertase enzymes and insulin itself.
163

Caractérisation des effets et des récepteurs de l'endothéline dans la vasculature utérine lors de la gestation chez la rate

Guérin, Pascale January 2006 (has links)
Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal
164

Design, synthesis and biological evaluation of new platelet aggregation inhibitors and novel methodologies for the preparation of CF₂R containing molecules

Khalaf, Ali 21 February 2013 (has links) (PDF)
The first part of the thesis deals with the synthesis and biological evaluation of new platelets aggregation inhibitors, based on 12-HETE, 13-HODE and their analogues. In the second part we are interested in novel methodologies for the preparation of CF₂-containing molecules : First, a flexible strategy for the synthesis of gem-difluoro-bisarylic derivatives and heteroaromatic analogues was designed based on the easy synthesis and the reactivity of gem-difluoro propargylic intermediates, which by Diels-Alder cycloaddition and 1,3-dipolar cycloadditions afforded respectively the bisarylic and mixed arylic heteroarylic scaffolds. In addition, two small libraries were constructed around a bisarylic scaffold as representative examples. Second, we were interested in the synthesis of optically active functionalized molecules containing a gem-difluoro group, using asymmetric organocatalysis protocols. After preparation of the gem-difluoro enals, from their difluoropropargylic precursors, asymmetric organocalytic Diels-Alder cycloaddition and 1,4-conjugated additions were successfully performed.
165

Effect of selective COX-2 inhibitors on hepatic progenitor cells and the pathologies of experimental hepatocarcinogenesis

Davies, Richard January 2007 (has links)
[Truncated abstract] Hepatocellular carcinoma (HCC) is the major malignancy complicating chronic liver disease. New therapies for the prevention of HCC are required due to the limited success and high tumour recurrence rates of existing treatments. Emerging evidence suggests that HCC arise from the transformation of adult liver progenitor cells (LPCs), which have the capacity to differentiate into hepatocytes and biliary cells during liver regeneration. LPC activation precedes neoplasia in experimental hepatocarcinogenesis. LPCs share antigenic epitopes with HCCs, including α-fetoprotein (AFP) and M2- pyruvate kinase (M2PK). In animal models of hepatocarcinogenesis, attenuation of the LPC response reduces the incidence of HCC following prolonged liver injury via a tumour necrosis factor (TNF) dependent mechanism. As TNF is a pro-inflammatory cytokine, these data suggest that anti-inflammatory agents may be effective in inhibiting LPC activation and hepatocarcinogenesis. Cyclo-oxygenase-2 (COX-2) is an inducible enzyme that mediates the production of many prostaglandins during inflammation and carcinogenesis. Recent investigations show that the administration of selective COX-2 inhibitors (SC2Is) may reduce the incidence of a variety of tumours including breast, colon and skin. The broad aim of this thesis was to conduct a series of detailed studies on the effects of a SC2I on LPC activation and the hepatic pathologies associated with hepatocarcinogenesis in order to test the hypothesis that S2CIs may be a beneficial therapy that can reduce liver injury and pre-neoplastic changes in the choline-deficient, ethionine supplemented (CDE) murine model of hepatocarcinogenesis. Administration of a SC2I (SC-236) significantly inhibited a variety of hepatic cell populations that expand during the first month of the CDE mouse model of hepatocarcinogenesis (a choline deficient, ethionine supplemented diet). Numbers of M2PK-positive LPCs (which are more hepatocytic in morphology and are also COX-2 positive) and inflammatory cells were all significantly reduced by SC-236. In contrast, numbers of A6-positive LPCs (which are more biliary cell-like in morphology and do not express COX-2) were unchanged. ... In summary, these data suggest that COX-2 inhibitors such as SC-236 inhibit LPC activation and a variety of pre-neoplastic liver pathologies as a result of COX-2 dependent and independent mechanisms that may be mediated through inhibition of Akt phosphorylation and induction of apoptosis. Moreover, SC2Is may be useful as preventative treatment strategies for HCC in patients with chronic liver disease.
166

Yaşlı ratlarda selektif ve non selektif cox inhibitörlerinin NMDA reseptör subunitlerine etkisi /

Öztürk, Özlem. Altuntaş, İrfan. January 2006 (has links) (PDF)
Tez (Tıpta Uzmanlık) - Süleyman Demirel Üniversitesi, Tıp Fakültesi, Biyokimya Anabilim Dalı, 2006. / Bibliyografya var.
167

Avaliação farmacocinética, hematológica e espermática de pôneis tratados com meloxicam / Pharmacokinetics, hematological and spermatic parameters in ponies treated with meloxicam

Pozzobon, Ricardo 15 July 2010 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most used drugs in veterinary medicine. Most of the original NSAIDs inhibit primarily cyclooxygenase-1 (COX-1) and cause adverse effects such as gastrointestinal ulcers, kidney and liver damage. When the formerly supposed anti-inflammatory COX-2 enzyme was discovered, NSAIDs were developed to selectively inhibit this enzyme. Today it is known that COX-2 is not exclusively expressed in inflammatory conditions; it also has physiologic functions in tissues such as brain, male and female reproductive tracts. Several horses, such as stallions, are treated with some NSAID, and many times these treatments are prolonged as in osteoarthritis and laminitis. In horses, there is still little information about the effects of COX-1 and COX-2 selective NSAIDs on the reproductive and cardiovascular systems. Pharmacokinetic information of NSAIDs, like meloxicam, in different health conditions and horse breeds may explain differences in efficiency and/or toxicity. This study evaluated meloxicam pharmacokinetics on 3 groups with 3 animals each: a group of ponies with induced synovitis, a group of healthy ponies and a group of healthy horses. All animals were treated with the recommended dosage (0.06 mg/kg, PO) of meloxicam. Plasma was obtained from blood samples collected before (time 0), 15 and 30 minutes, and 1, 2, 4, 8, 12 and 24 hours after medication. The time to reach the maximum plasma concentration (Tmax) was longest (P<0.05) in horses and the maximum concentration (Cmax) was highest (P<0.05) in healthy ponies. The initial plasma concentrations were achieved more quickly (P<0.05) in both ponies groups. In a second study, the effect of meloxicam (preferential COX-2 NSAID) and ketoprofen (unspecific NSAID) was evaluated on hematological and biochemical variables, on the gastric mucosa and on semen quality of 6 healthy pony stallions. The ponies were treated for 30 days and then the experiment was repeated a second time changing the ponies group in a latin square design. The stallions were distributed equally into 3 groups; one was treated with meloxicam (0.6 mg/kg oral administration, PO; n=6), another with ketoprofen (2.2 mg/kg, PO; n=6, positive control) and the negative control group (n=6) received no treatment. Blood samples were obtained once a week for six weeks, beginning before treatment and extending until 1 week after the treatment ended to evaluate hematologic, coagulation and biochemical (AP, AST and GGT) profiles. Gastroscopic evaluation was determined 1 week before and 1 week after the treatment ended. Semen was collected and evaluated twice a week for 16 weeks: before treatment began (week 0), during 4 weeks of treatment (weeks 1-4), and 10 weeks after the treatment ended (weeks 5-15). Concentration of total prostaglandins (PGs) was measured in the seminal plasma of ejaculates collected before (week 0), during (1 to 4 weeks) and after treatment (week 5 and week 15). The treatments did not alter any evaluated hematological and biochemical parameter as well as on the gastric mucosa, but there was a time effect on fibrinogen, pro-thrombin time and activated partial thromboplastin time. Meloxicam treatment caused more (P<0.05) damage to the sperm membrane integrity and decreased (P<0.05) membrane function and total PGs concentration. A significant increase (P<0.05) in tail defects also was observed 2 weeks after treatment ended. In summary, pharmacokinetics differed between healthy ponies and those with synovitis. This may be the result of drug migration to the injury site. Meloxicam absorption was faster in ponies. No influence of the treatments was observed on the hematological or biochemical parameters as well as on gastric mucosa. Thirty day long meloxicam treatment lowered PGs in seminal plasma and affected semen quality. This suggests a physiological function of COX-2 in the stallion s reproductive tract. / Os anti-inflamatórios não esteroidais (AINEs) estão entre os fármacos mais utilizados na medicina veterinária. A maioria deles produz efeitos colaterais, como úlceras gastrointestinais, lesões renais e hepáticas, por inibirem a ciclooxigenase-1 (COX-1). Com a descoberta da COX-2, passaram a ser desenvolvidos AINEs para inibir seletivamente esta enzima, tida até pouco tempo como inflamatória. Porém, hoje se sabe que a COX-2 não é expressa exclusivamente em condições inflamatórias, mas também em funções fisiológicas em vários tecidos, como o cerebral, reprodutivo feminino e masculino. Vários eqüinos, como garanhões, são freqüentemente tratados com algum AINE, e muitas vezes esses tratamentos são prolongados como nos casos de osteoartrite e laminite. Além disto, são escassas as informações sobre os efeitos causados tanto pelos AINEs com inibição inespecífica de COX, como pelos ditos seletivos para a COX-2, especialmente sobre o sistema reprodutivo e cardiovascular de eqüinos. O conhecimento da farmacocinética de novos AINEs, como o meloxicam em diferentes condições de saúde e tamanho de eqüinos poderia explicar a sua eficácia ou efeito tóxico diversos. Desta forma, o estudo da farmacocinética do meloxicam oral foi realizado com três grupos distintos de eqüinos com três animais cada. Um grupo formado por pôneis com sinovite induzida, um grupo com pôneis saudáveis e outro grupo com cavalos saudáveis. Todos os animais foram tratados com a dose indicada (0,6 mg/kg via oral). As amostras de sangue para obtenção do plasma foram coletadas antes (tempo 0), 15, 30 minutos e 1, 2, 4, 8, 12 e 24 horas pós-medicação. O tempo da concentração máxima do fármaco (Tmax) foi mais tardio (P<0,05) nos cavalos e a concentração plasmática máxima (Cmax) foi maior (P<0,05) nos pôneis saudáveis. As primeiras concentrações plasmáticas foram atingidas mais rapidamente (P<0,05) nos grupos de pôneis. Para avaliar o efeito do meloxicam (AINE com ação preferencial sobre a COX-2) sobre os parâmetros hematológicos, bioquímicos, na mucosa gástrica, e sobre a qualidade do sêmen eqüino foram utilizados seis garanhões pôneis. Estes foram distribuídos em três grupos, sendo um tratado com meloxicam (0,6 mg/kg via oral), outro com cetoprofeno como controle positivo (2,2 mg/kg via oral; inibidor inespecífico de COX) durante 30 dias e um terceiro grupo não recebeu nenhum tratamento constituindo o grupo controle negativo. O experimento foi repetido três vezes alternando-se os pôneis de grupos num delineamento quadrado latino. Amostras de sangue foram coletadas antes (semana zero), durante (semanas um a quatro) e uma semana após o fim do tratamento (semana cinco) para determinação dos parâmetros hematológicos (hemograma e coagulograma) e bioquímicos (fosfatase alcalina - AP, aspartato aminotransferase - AST e gama-glutamil transferase - GGT). Também foram realizadas gastroscopias antes (semana zero) e após o final do tratamento (semana cinco). O sêmen foi coletado e avaliado duas vezes por semana antes (semana zero), durante (semanas um a quatro) e por 11 semanas após o final do tratamento (semanas cinco a 15). A concentração de prostaglandinas totais no plasma seminal foi avaliada nas semanas zero a cinco e na semana 15. Os tratamentos não modificaram nenhum parâmetro hematológico, bioquímico e gástrico avaliado, mas o tempo de coleta influenciou o fibrinogênio, tempo de pró-trombina e tempo de tromboplastina parcial ativada. O grupo tratado com meloxicam apresentou mais (P<0,05) espermatozóides com lesões de membrana e com diminuição da funcionalidade da membrana, bem como aumento significativo (P<0,05) de defeitos de cauda e diminuição (P<0,05) na concentração de prostaglandinas totais no plasma seminal, comparado aos grupos cetoprofeno e controle. Os parâmetros da farmacocinética diferiram entre os pôneis saudáveis e com sinovite. Isto pode ser atribuído a uma possível migração do fármaco para o local da lesão. A absorção do meloxicam foi mais rápida nos pôneis. Os tratamentos não influenciaram os parâmetros hematológicos, de coagulação, bioquímicos e na mucosa gástrica. O tratamento por 30 dias com meloxicam diminui a concentração de prostaglandinas totais no plasma seminal e interfere negativamente na qualidade do sêmen, sugerindo uma ação fisiológica da COX-2 no tecido reprodutivo de garanhões.
168

Avaliação histométrica do reparo ósseo alveolar de ratos tratados com anti-inflamatórios não-esteroidais / Histometric evaluation of alveolar bone repair in rats treated with non-steroidal anti-inflamatory

Ricardo Nogueira Fracon 03 July 2009 (has links)
As prostaglandinas (PGs) são derivadas do metabolismo do ácido aracdônico pela via das enzimas cicloxigenases (COX-1 e COX-2) e participam do controle do metabolismo ósseo. Os anti-inflamatórios não-esteroidais (AINEs), inibidores das COX, podem interferir negativamente com a formação óssea, atrasando o reparo de fratura de ossos longos, a fusão espinhal e a osseointegração de implantes. O presente trabalho teve por objetivo avaliar, quantitativamente, o efeito de diferentes tipos de AINEs (convencional, preferencial e seletivo para COX-2), assim como de um analgésico com efeito anti-inflamatório fraco, sobre o reparo ósseo alveolar, em ratos machos. Os animais foram divididos em 5 grupos experimentais: a) controle (administração de 1 mL água/dia), b) cetorolaco de trometamina (inibidor não-seletivo COX-1/COX-2; ingestão de 4 mg/kg/dia), c) nimesulida (inibidor preferencial de COX-2; ingestão de 5 mg/kg/dia), d) paracetamol (efeito anti-inflamatório fraco; ingestão de 80 mg/kg/dia), e) etoricoxibe (inibidor seletivo de COX-2; ingestão de 10 mg/kg/dia). As dosagens foram baseadas em trabalhos experimentais da literatura e na equivalência com a terapêutica humana. A administração foi realizada por gavage gástrica, iniciando logo após a extração do incisivo superior direito e seguindo por um periódo de 14 dias, após o que os ratos foram sacrificados, as hemi-maxilas contendo os alvéolos em reparação foram coletadas e processadas para inclusão em parafina, orientada de maneira a permitir cortes semi-seriados longitudinais de 6 &mu;m de espessura (a intervalos de 60 &mu;m), que foram corados pela hematoxilina e eosina. O percentual de tecido ósseo neoformado foi estimado por método de contagem diferencial de pontos, utilizando-se um microscópio óptico munido de câmera digital de vídeo para captura de imagens e um programa para histometria. Foram contados cerca de 1200 pontos (1182,9 ± 47,6 pontos; média ± EPM) no terço cervical alveolar de cada animal, em cerca de 8 secções histológicas intercaladas (8,6 ± 0,3 secções; média ± EPM). Após a aplicação de teste que comprovou a normalidade de todas as distribuições (teste de Kolmogorov-Smirnov, p > 0,10) aplicou-se a Análise de Variância (gl=4; F = 1,52; x2 = 0,13), que comprovou que o tratamento com os diferentes tipos de AINEs não interferiu com a formação óssea reparacional, neste modelo experimental. Os presentes resultados, obtidos em animais, não devem ser diretamente extrapolados para humanos, nem conduzir a uma inferência sobre o uso de AINEs na clínica odontológica. No entanto, as numerosas evidências experimentais e clínicas de que os diferentes tipos de AINEs podem ter efeitos indesejados na clínica ortopédica, somadas ao número reduzido de estudos voltados especificamente para a área odontológica, indicam a necessidade de mais investigações nessa área, com variação dos parâmetros experimentais e das ferramentas de avaliação, antes que se descarte a possibilidade de que os AINEs possam ter efeitos indesejados em procedimentos odontológicos que necessitam de formação óssea, principalmente no caso de utilização prolongada. / The cyclooxygenase enzymes COX-1 and COX-2 catalyze the conversion of arachidonic acid to prostaglandins (PGs), eicosanoids important for control of bone metabolism. The non-steroidal anti-inflammatory drugs (NSAIDs), which are COX inhibitors, may negatively interfere with bone formation and delay long bone fracture healing, spinal fusion and implant osseointegration. The aim of the present study was to investigate quantitatively whether different types of NSAIDs (conventional, preferential and COX-2-selective), as well as an analgesic drug with a weak anti-inflammatory action, can hinder alveolar bone healing, in male rats. The animals were divided in 5 experimental groups: a) control (oral administration of 1 mL water/day), b) cetorolac (non-selective COX-1/COX-2 inhibito - 4 mg/kg/day oral dose), c) nimesulide (preferential COX-2 inhibitor - 5 mg/kg/day oral dose), paracetamol (weak anti-inflammatory - 80 mg/kg/day oral dose), etoricoxib (selective COX-2 inhibitor - 10 mg/kg/day oral dose). The doses of NSAIDs were compatible to human therapy and in the range of investigations carried out in laboratory animals. The drugs were administered by gavage from the day of extraction of the upper right incisors until death 2 weeks later, when the hemi-maxillae containing the alveolar sockets were collected, decalcified and processed for paraffin embedding. Semi-serial longitudinal 6-&mu;m-thick sections were cut at 60-&mu;m intervals and stained with hematoxylin and eosin. The degree of new bone formation inside the alveolar socket was estimated by a differential point-counting method, using an optical microscopy with a digital camera for image capture and a public domain histometry software. A total of 1182,9 ± 47,6 points (mean ± SEM) were counted in the cervical alveolar third, in 8,6 ± 0,3 (mean ± SEM) histological sections per alveolus (final magnification 100x), the percentage of points lying on bone trabeculae being proportional to their volume density. After confirmation of a normal distribution (Kolmogorov-Smirnov normality test, p>0,10) and comparison among groups by Analysis of Variance (gl = 4; F = 1,52; x2 = 0,13), histometric data confirmed that none of the anti-inflammatory drugs have detrimental effects in the volume fraction of new bone trabeculae filling the tooth extraction socket. Although experimental results obtained in animals may not be directly extrapolated to human neither induce to inferences about the clinical use of NSAIDs, numerous evidences have confirmed the deleterious effects of NSAIDs in the orthopedic clinic. Considering the reduced amount of studies on this subject pertaining to the dental field, more investigations are needed varying the experimental parameters and techniques, before the possibility of deleterious effects of NSAIDs in dental procedures requiring new bone formation are discharged.
169

Estudo de neoplasias mamárias de cadelas em Uberlândia e imunomarcação para ciclooxigenase 2 / Research of mammary tumors in female dogs in Uberlândia and cyclooxygenase 2 immunostaining

Soares, Nicolle Pereira 22 May 2015 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The cyclooxygenase 2 (Cox 2) is a molecular indicator of prognosis marker and its expression is associated with progression of mammary tumors in dogs. The purpose of this study was to investigate breast tumors of bitches Cox 2 expression by immunohistochemistry and correlated with the clinical stage, tumor size, lymph node involvement, the classification and the histological grade of carcinomas. We included in this study, 100 female dogs with mammary tumors and 131 samples were analyzed. Histological and COX 2 immunostaining evaluation were conducted. The streptavidin-biotinaperoxidase technique was used in order to do the immunohistochemistry (IHC). The IHC analysis was performaced counting the number of positive-staining cells in ten fields and the staining intensity. The COX 2 staining index was obtained by multiplying the COX 2 staining distribution and intensity scores. This gave a range of COX 2 staining indices of 0 12.Carcinoma complex was the most common histological type that we were diagnosed. The COX 2 expression was observed in the benign and malignant tumors. The weak score is more frequent, and strong score was observed in carcinomas. Simple carcinomas demonstraded a higher number of positive staining cells. There was no positive correlation between the histological type, size and lymph node involvement and the Cox 2 immunostaining. Therefore, COX 2 immunostaining is not a good prognostic factor. / A ciclooxigenase 2 (Cox 2) é um marcador molecular indicador de prognóstico e sua expressão está relacionada com a progressão do tumor mamário na cadela. Tendo isso em vista, o objetivo deste trabalho foi investigar tumores mamários de cadelas a expressão de Cox 2 por meio de imunohistoquímica e correlacionar com o estadiamento clínico, o tamanho tumoral, o envolvimento linfonodal, a classificação e o grau histológico dos carcinomas. Foram incluídas neste estudo, 100 cadelas com neoplasia mamária e dessas, 131 amostras foram analisadas. A avaliação histológica e da imunomarcação de Cox 2 foram conduzidas. Para a imunohistoquímica (IHQ), utilizou-se a técnica de estreptoavidina-biotinaperoxidase. Para análise das lâminas de IHQ contou-se o número de células marcadas em dez campos e verificou-se a intensidade de marcação. O escore de marcação foi obtido pelo produto do número de células marcadas e a intensidade de marcação. O tipo histológico mais frequente diagnosticado foi o carcinoma complexo mamário. A expressão de Cox 2 foi observada nos tumores benignos e malignos. A marcação fraca é mais frequente, sendo a marcação forte observada nos carcinomas. Os carcinomas simples apresentaram maior número de células marcadas. Não houve correlação positiva entre o tipo histológico, tamanho e o envolvimento linfonodal e a imunomarcação de Cox 2. Sendo assim, a imunomarcação de Cox 2 não demonstrou ser um bom fator de prognóstico. / Mestre em Ciências Veterinárias
170

Análise de polimorfismos do gene ciclooxigenase-2 (COX-2) no câncer colorretal / Analysis of the cyclooxygenase-2 (COX-2) gene polymorphisms in colorectal cancer

Michele Tatiana Pereira Tomitão 03 February 2016 (has links)
A População brasileira apresenta elevada diversidade genética devido à multietnicidade, que têm implicações clínicas/genéticas importantes. O estudo de genes polimórficos pode auxiliar na detecção de pessoas com maior risco de desenvolver câncer, caracterização de evolução diferenciada, resposta distinta ao tratamento quimioterápico ou radioterápico e prognóstico. A ciclooxigenase-2 (COX-2) é induzida em resposta ao fator de crescimento e citocinas, sendo expressa nas doenças inflamatórias, lesões pré-malignas e tumores colorretais. Este trabalho teve como objetivos avaliar a influência dos polimorfismos 1195A > G e 8473T > C do gene COX-2 como fatores de risco para o desenvolvimento de câncer colorretal e investigar o impacto dos polimorfismos na progressão e sobrevida de pacientes submetidos ao tratamento cirúrgico por câncer colorretal. Avaliaram-se SNPs (polimorfismos de nucleotídeo único) em 230 pacientes submetidos à ressecção cirúrgica no Hospital das Clínicas (SP), seguidos por 5 anos e 196 controles, operados por doença benigna na mesma instituição, pareados quanto ao sexo e idade, sem histórico individual ou familial de câncer. Isolou-se o DNA dos leucócitos utilizando-se do kit de extração e purificação PureLink DNA Minikit, seguido de amplificação pela reação em cadeia da polimerase (PCR). Utilizou-se a análise do PCR em Tempo Real para determinar os genoótipos os polimorfismos através dos ensaios TaqMan ® SNP Genotyping Assay. Os resultados encontrados foram associados aos dados epidemiológicos e clinicopatológicos dos pacientes. Determinaram-se as frequências genotípicas, alélicas e estimaram-se as frequências de haplótipos dos polimorfismos do COX-2 -1195A > G e 8473T > C. As populações estão em equilíbrio de Hardy-Weinberg, a exceção do grupo controle para o polimorfismo 8473T > C (p=0,02). As frequências foram similares nos grupos caso e controle para genótipos e haplótipos, portanto, não há associação entre esses polimorfismos e risco de CCR. Em relação às variáveis epidemiológicas e anatomopatológicas do grupo caso, demonstraram-se associação das mesmas com alguns perfis genotípicos. Encontrou-se frequência elevada do genótipo polimórfico -1195GG na população oriental, grupo constituído em sua maioria por japoneses, e dos genótipos 8473TC e CC em afrodescendentes (p < 0,05). Neste grupo, o genótipo -1195GG é ausente. Foi encontrada. Encontrou-se associação entre invasão angiolinfática e genótipo polimórfico 8473 CC (p < 0,05). Na análise de sobrevida, houve associação, no modelo codominante e dominante, do genótipo COX-2 -1195GG com menor sobrevida global (AAxGG: RR = 2,78; IC95% = 1,13-6,84; p < 0,020 e AA/AG x GG: RR = 2,59; IC95% = 1,07-6,27; p < 0,04), utilizando o modelo de regressão múltipla, ajustado para as variáveis de confusão. Assim, pode-se concluir que as variantes -1195A > G e 8473T > C não participam da suscetibilidade genética ao CCR na população brasileira. O polimorfismo -1195A > G, associado à menor sobrevida, pode atuar como marcador prognóstico nestes pacientes / Brazilian population displays very high levels of genomic diversity due to the multi-ethnicity, which have important clinical/genomic implications. Polymorphic genes\' study may aid in the detection of people at higher risk of developing cancer, characterization of differentiated outcome, distinctive response to chemotherapy or radiotherapy and prognosis. Cyclooxygenase-2 (COX-2) is induced in response to growth factor and cytokines, and it is expressed in inflammatory diseases, precancerous lesions and colorectal tumors. This study aimed to evaluate the influence of COX-2 -1195A> G and 8473T> C gene polymorphisms as a risk factor for developing colorectal cancer and to investigate the impact of polymorphisms on progression and survival in patients who have undergone surgical treatment for colorectal cancer. We evaluated SNPs (Single nucleotide Polymorphism) of 230 colorectal cancer resected patients admitted at the Hospital das Clinicas (SP), followed by 5 years, and 196 controls, operated for benign disease at the same institution, matched for age and sex, and no individual or familial history of cancer. DNA was isolated from leukocyte using PureLink (TM) Genomic DNA Mini Kit, followed by amplification by polymerase chain reaction (PCR). Real-time analysis was used for genotyping of polymorphisms, through the TaqMan ® SNP Genotyping Assay. The results of the polymorphisms were associated to epidemiological, clinicopathological and immunohistochemical features of the patients. Were determined genotype and allelic frequencies, and were estimated the haplotype frequencies of COX-2 -1195A > G and 8473T > C polymorphisms. The populations are in Hardy-Weinberg equilibrium, except for the control group to the 8473T > C polymorphism (p = 0,02). The frequencies were similar in case and control groups for genotypes and haplotypes, therefore, there is no association between these polymorphisms and risk of CCR. Regarding the epidemiological and pathological variables in the case group, we demonstrate their association with some genotypic profiles. A high frequency of the polymorphic genotype -1195GG was found in an Asiatic population, group composed in its majority by Japaneses, and 8473TC and CC genotypes in African descent (p < 0,05). In this group, the 1195GG genotype is absent. Association was found between angiolymphatic invasion and polymorphic genotype 8473 CC (p < 0,05). In survival analysis, there was an association, in co-dominant and dominant model, of the COX-2 genotype -1195GG with decreased overall survival (AAxGG: RR = 2,78, 95% CI 1,13-6,84; p < 0,020 and AA / AG x GG: RR = 2,59, 95% CI 1,07-6,27; p < 0,04), using the multiple regression model, adjusted for confounding variables. Therefore, -1195A variants > G and 8473T > C does not appear participate in genetic susceptibility to CCR in the Brazilian population, but the polymorphism -1195A > G, associated with decreased survival, may act as a prognostic marker in these patients

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