936 resultados para Interacção lípido-proteína
Resumo:
Introdução: existem múltiplos estudos acerca da interacção entre o ácido valpróico (AVP) e o meropenem, mas não estão bem definidas as recomendações para o seu uso concomitante, visto haver uns que indicam que os dois fármacos não devem ser administrados juntos e outros que apenas recomendam que os níveis de valproatémia sejam monitorizados. Também não existe informação consistente sobre possíveis repercussões clínicas desta interacção. O objectivo deste estudo foi analisar a interacção entre o AVP e o meropenem e as suas repercussões clínicas, em doentes hospitalizados e cronicamente medicados com o primeiro. Material e Métodos: trata-se de um estudo retrospectivo de uma amostra de doentes internados num hospital distrital no período de um ano. Os critérios de inclusão foram a existência de pelo menos uma determinação do nível sérico de AVP na semana anterior à prescrição de meropenem e outra durante o tratamento concomitante com os dois fármacos. Foi efectuada a análise estatística de 18 episódios. Resultados: Verificou-se um declínio médio estatisticamente significativo (p<0,001) de cerca de 83,4% dos níveis séricos de AVP após o início da terapêutica com meropenem e foram objectivadas crises convulsivas em 50% dos doentes. Discussão: a interacção entre os dois fármacos em questão é potencialmente grave, sendo que o número de doentes com manifestações clínicas desta interacção é maior que em estudos semelhantes. Conclusão: concluiu-se que a utilização concomitante dos dois fármacos deve ser evitada.
Resumo:
Fertilization is a multistep and complex process culminating in the merge of gamete membranes, cytoplasmic unity and fusion of genome. CD81 is a tetraspanin protein that participates in sperm-oocyte interaction, being present at the oocyte surface. CD81 has also been implicated in other biological processes, however its specific function and molecular mechanisms of action remain to be elucidated. The interaction between CD81 and its binding partner proteins may underlie the CD81 involvement in a variety of cellular processes and modulate CD81/interactors specific functions. Interestingly, in a Yeast two Hybrid system previously performed in our lab, CD81 has emerged as a putative interactor of the Amyloid Precursor Protein (APP). In the work here described, bioinformatics analyses of CD81 interacting proteins were performed and the retrieved information used to construct a protein-protein interaction network, as well as to perform Gene Ontology enrichment analyses. CD81 expression was further evaluated in CHO, GC-1 and SH-SY5Y cell lines, and in human sperm cells. Additionally, its subcellular localization was analyzed in sperm cells and in the neuronal-like SH-SY5Y cell line. Subsequently, coimmunoprecipitation assays were performed in CHO and SH-SY5Y cells to attempt to prove the physical interaction between CD81 and APP. A functional interaction between these two proteins was accessed thought the analyses of the effects of CD81 overexpression on APP levels. A co-localization analysis of CD81 and some interactors proteins retrieved from the bioinformatics analyses, such as APP, AKT1 and cytoskeleton-related proteins, was also performed in sperm cells and in SH-SY5Y cells. The effects of CD81 in cytoskeleton remodeling was evaluated in SH-SY5Y cells through monitoring the effects of CD81 overexpression in actin and tubulin levels, and analyzing the colocalization between overexpressed CD81 and F-actin. Our results showed that CD81 is expressed in all cell lines tested, and also provided the first evidence of the presence of CD81 in human sperm cells. CD81 immunoreactivity was predominantly detected in the sperm head, including the acrosome membrane, and in the midpiece, where it co-localized with APP, as well as in the post-acrosomal region. Furthermore, CD81 co-localizes with APP in the plasma membrane and in cellular projections in SH-SY5Y cells, where CD81 overexpression has an influence on APP levels, also visible in CHO cells. The analysis of CD81 interacting proteins such as AKT1 and cytoskeletonrelated proteins showed that CD81 is involved in a variety of pathways that may underlie cytoskeleton remodeling events, related to processes such as sperm motility, cell migration and neuritogenesis. These results deepen our understanding on the functions of CD81 and some of its interactors in sperm and neuronal cells.
Resumo:
Com o forte crescimento tecnológico tem-se verificado, cada vez mais, o crescente aumento de Web sites, voltados para o contacto directo com o consumidor, onde é possível procurar, escolher e adquirir um determinado produto I serviço directamente ao fornecedor. As plataformas de suporte à pesquisa de produtos de turismo possibilitam a entrega de um grande volume de dados mediante a pesquisa efectuada. Esta informação é, na sua maior parte, informação textual e é geralmente disponibilizada ao utilizador (via uma página Web) sob a forma de uma listagem ou tabela. Este trabalho incide então sobre a proposta e implementação de um conjunto de interfaces com elevada ergonomia, que permitam uma interacção simples e intuitiva entre o utilizador e os dados de turismo, mais concretamente com reservas de aviação e hotel. Para este propósito foi desenvolvida uma Rich Internet Application que permite ao utilizador o ajuste de determinados factores, que influenciam estes produtos de turismo, de modo a encontrar com maior facilidade o que mais se enquadra nos seus gostos I objectivos no vasto conjunto de resultados da pesquisa. ABSTRACT; With the constant growth of information technology tools we have witnessed increase in the number of web Sites aimed to direct contact with the consumer, where users can search, select and purchase a product/service directly to the supplier. The platforms that support the search for tourism data enable the delivery of a large volume of data, as a result of the search that was done. This information is mostly textual and is, in general available to the user (via a web page) in a form of a large list or table. This work focuses on a proposal and implementation of a set of interfaces with high ergonomics. allowing a simple and intuitive interaction between the user and the tourism data, more specifically with air fares and hotels reservations. For this purpose was developed an Rich Internet Application that allows the user to adjust some factors that influence the tourism products, in order to more accurately find what fits their tastes objectives in the wide range of search results.
Resumo:
Se estudia la efectividad del factor de crecimiento BMP-7 en la artrodesis de columna lumbar. La efectividad se basa en la eficacia clínica, la seguridad y los resultados estudiados mediante imágenes radiográficas y de tomografía computadorizada concluyendo que la combinación de BMP-7 - aloinjerto es más efectiva que aloinjerto solo.
Resumo:
Reactive oxygen species (ROS) are produced by aerobic metabolism and react with biomolecules, such as lipids, proteins and DNA. In high concentration, they lead to oxidative stress. Among ROS, singlet oxygen (1O2) is one of the main ROS involved in oxidative stress and is one of the most reactive forms of molecular oxygen. The exposure of some dyes, such as methylene blue (MB) to light (MB+VL), is able to generate 1O2 and it is the principle involved in photodynamic therapy (PDT). 1O2 e other ROS have caused toxic and carcinogenic effects and have been associated with ageing, neurodegenerative diseases and cancer. Oxidative DNA damage is mainly repaired by base excision repair (BER) pathway. However, recent studies have observed the involvement of nucleotide excision repair (NER) factors in the repair of this type of injury. One of these factors is the Xeroderma Pigmentosum Complementation Group A (XPA) protein, which acts with other proteins in DNA damage recognition and in the recruitment of other repair factors. Moreover, oxidative agents such as 1O2 can induce gene expression. In this context, this study aimed at evaluating the response of XPA-deficient cells after treatment with photosensitized MB. For this purpose, we analyzed the cell viability and occurrence of oxidative DNA damage in cells lines proficient and deficient in XPA after treatment with MB+VL, and evaluated the expression of this enzyme in proficient and complemented cells. Our results indicate an increased resistance to treatment of complemented cells and a higher level of oxidative damage in the deficient cell lines. Furthermore, the treatment was able to modulate the XPA expression up to 24 hours later. These results indicate a direct evidence for the involvement of NER enzymes in the repair of oxidative damage. Besides, a better understanding of the effects of PDT on the induction of gene expression could be provided
Resumo:
studies using UV as a source of DNA damage. However, even though unrepaired UV-induced DNA damages are related to mutagenesis, cell death and tumorigenesis, they do not explain phenotypes such as neurodegeneration and internal tumors observed in patients with syndromes like Xeroderma Pigmentosum (XP) and Cockayne Syndrome (CS) that are associated with NER deficiency. Recent evidences point to a role of NER in the repair of 8-oxodG, a typical substrate of Base Excision Repair (BER). Since deficiencies in BER result in genomic instability, neurodegenerative diseases and cancer, it was investigated in this research the impact of XPC deficiency on BER functions in human cells. It was analyzed both the expression and the cellular localization of APE1, OGG1 e PARP-1, the mainly BER enzymes, in different NER-deficient human fibroblasts. The endogenous levels of these enzymes are reduced in XPC deficient cells. Surprisingly, XP-C fibroblasts were more resistant to oxidative agents than the other NER deficient fibroblasts, despite presenting the highest of 8-oxodG. Furthermore, subtle changes in the nuclear and mitochondrial localization of APE1 were detected in XP-C fibroblasts. To confirm the impact of XPC deficiency in the regulation of APE1 and OGG1 expression and activity, we constructed a XPC-complemented cell line. Although the XPC complementation was only partial, we found that XPC-complemented cells presented increased levels of OGG1 than XPC-deficient cells. The extracts from XPC-complemented cells also presented an elevated OGG1 enzimatic activity. However, it was not observed changes in APE1 expression and activity in the XPCcomplemented cells. In addition, we found that full-length APE1 (37 kDa) and OGG1- α are in the mitochondria of XPC-deficient fibroblasts and XPC-complemented fibroblasts before and after induction of oxidative stress. On the other hand, the expression of APE1 and PARP-1 are not altered in brain and liver of XPC knockout mice. However, XPC deficiency changed the APE1 localization in hypoccampus and hypothalamus. We also observed a physical interaction between XPC and APE1 proteins in human cells. In conclusion, the data suggest that XPC protein has a role in the regulation of OGG1 expression and activity in human cells and is involved mainly in the regulation of APE1 localization in mice. Aditionally, the response of NER deficient cells under oxidative stress may not be only associated to the NER deficiency per se, but it may include the new functions of NER enzymes in regulation of expression and cell localization of BER proteins
Resumo:
A produção e qualidade do leite são influenciadas por factores ambientais como a nutrição, factores genéticos como a raça, e factores fisiológicos como a idade a idade ao parto ou o número de ordenhas diárias. Este trabalho teve por objectivo estimar factores de correcção para os efeitos ambientais que influenciam a quantidade e qualidade do leite com vista ao melhoramento genético dos animais. Para isso, foram utilizados os registos de 23897 contrastes leiteiros de vacas de raça Frísia, no período de 6 anos, recolhidos a partir dos dados da ANABLE. De acordo com os resultados, obtidos através do método dos quadrados mínimos, observa-se que para a produção de leite, gordura e proteína, todos os efeitos fixos de variação são significativos nas três características produtivas estudadas, pelo que se conclui que há interacção entre a idade da vaca ao parto e a produção e qualidade do leite, assim como, a época do ano em que ocorre o parto e o número de ordenhas diárias a que o animal está sujeito. ABSTRACT; Cow production and milk quality are influenced by environmental factors such as nutrition, by genetic factors as breed and physiological factors as age at calving or milking frequency. This study aimed to estimate correction parameters for environmental factors with influence on milk production and quality embodying genetic improvement. For this propose, a data base was used with information related to 23987 milk tests collected from official milk recording program. According to the results, where the at least square procedure was adopted, it shows that all the fixed effects of variation significantly affect the productive performances, so it can be concluded that there is a significant interaction between milking frequency, age at calving and season when it occurs, and milk production and quality.
Resumo:
Flowering is a fundamental process in the life cycle for plant. This process is marked by vegetative to reproductive apical meristem conversion, due to interactions between several factors, both internal and external to plant. Therefore, eight subtractive libraries were constructed using apical meristem induced or not induced for two contrasting species: Solanum lycopersicum cv. Micro-Tom and Solanum pimpinellifolium. Several cDNAs were identified and among these, were selected two cDNAs: one homologous cDNA to cyclophilin (LeCYP1) and the other to Auxin repressed protein (ARP). It has observed that LeCYP1 and ARP genes are important in the developmental process to plants. In silico analysis, were used several databases with the exclusion criterion E-value <1.0x10-15. As a result, conservation was observed for proteins analyzed by means of multiple alignments and the presence of functional domains. Then, overexpression cassettes were constructed for the ARP cDNA in sense and antisense orientations. For this step, it was used the CaMV35S promoter. The cDNA orientation (sense or antisense) in relation to the promoter was determined by restriction enzymes and sequencing. Then, this cassette was transferred to binary vector pZP211 and these cassettes were transferred into Agrobacterium tumefaciens LBA4404. S. lycopersicum cv. Micro-Tom (MT) and MT-Rg1 plants were transformed. In addition, seedlings were subjected to hormone treatments using a synthetic auxin (- naphthalene acetic acid) and cyclosporin A (cyclophilin inhibitor) treatments and it was found that the hormone treatment there were changes in development of lateral roots pattern, probably related to decreases in auxin signaling caused by reduction of LeCYP1 in MT-dgt plants while cyclosporin A treatments, there was a slight delay in flowering in cv. MT plants. Furthermore, assay with real-time PCR (RT-qPCR) were done for expression level analysis from LeCYP1 and ARP in order to functionally characterize these sequences in tomato plants.
Resumo:
Dissertação para obtenção do grau de Mestre no Instituto Superior de Ciências da Saúde Egas Moniz
Resumo:
Com o objectivo de estudar uma possível optimização da adubação mineral de trigo mole e sua interacção com estrumação, foi desenvolvido um ensaio onde, numa área com trigo mole, regado e em sementeira directa, se interagiram os 3 macronutrientes principais, com 3 níveis de estrume. Para esta interacção foram analisados vários parâmetros que resultaram em 3 parâmetros principais, produção de grão, de palha e também as extracções totais de N, P, K da cultura. De acordo com os resultados obtidos pôde-se verificar que a aplicação de estrume não revelou efeitos positivos na produção de grão/palha do trigo. A elevada fertilidade do solo em sementeira directa ofereceu à cultura uma base sustentável para o seu desenvolvimento sem que seja necessária a adubação mineral actualmente padronizada. Por fim foi evidente a importância da antecipação da 1ª cobertura realizada no trigo para o estado de afilhamento, factor que contribuiu significativamente para o sucesso da cultura; Optimization of mineral fertilizer in irrigated wheat and its interaction with the level of manure ABSTRACT: With the aim of studying the optimization of mineral fertilization of common wheat and their interaction with manure, it was developed a study where in an area with soft wheat, watered and with no tillage, we interacted 3 main macronutrients and 3 manure levels. To this interaction were analyzed several parameters that resulted in three major parameters, production of grain and straw and also the total extraction of N, P, K culture. According to the results it was observed that the application of manure did not show positive effects in the production of grain / wheat straw. The high soil fertility on direct seeding culture offered a sustainable base for its development without requiring high fertilization. Finally it was evident the importance of the anticipation of the 1st cover held in wheat, a factor that contributed significantly to the success of the crop.
Resumo:
Antecedentes: la proteína C reactiva es uno de los marcadores inflamatorios denominados “reactantes de fase aguda” que se produce en el hígado en respuesta a procesos infecciosos o inflamatorios. En los pacientes con tuberculosis se ha descrito la formación de anticuerpos anticitoplasma de neutrófi los (ANCA). Objetivo: determinar la concentración de proteína C reactiva, evaluar su comportamiento como marcador de la respuesta inflamatoria y analizar su correlación con los ANCA en los pacientes con tuberculosis pulmonar, antes y después de iniciar el tratamiento antifímico. Pacientes: se eligieron pacientes con sospecha de tuberculosis pulmonar. Una vez confirmado el diagnóstico, se obtuvieron las muestras de suero para analizar los datos clínicos y de laboratorios. La determinación de ANCA se realizó con estuches comerciales de inmunofluorescencia y la de proteína C reactiva con ELISA, antes y después de iniciar el tratamiento antifímico. Resultados: se obtuvieron 50 muestras de suero de pacientes con tuberculosis pulmonar. En la primera (94%) y segunda obtención (90%) de los sueros se registró un valor de proteína C reactiva menor de 5 mg/L. El valor promedio de proteína C reactiva fue de 3.05 ± 8.27 mg/L en la primera muestra y de 4.49 ± 11.2 mg/L en la segunda (p = 0.46). Los pacientes positivos a ANCA tuvieron valores más altos de proteína C reactiva en su segunda muestra (p = 0.001). Discusión: existe una asociación entre la proteína C reactiva y la producción de anticuerpos anticitoplasma de neutrófilos en un subgrupo de pacientes con tuberculosis pulmonar. Su significación es incierta, pero quizá desempeñan alguna función patogénica en la respuesta inflamatoria pulmonar.
Resumo:
Gran parte de los sistemas de producción de rumiantes se encuentran ubicados en el trópico seco, donde las condiciones medioambientales son difíciles y la base de la alimentación son pastos que en su momento no aportan los niveles adecuados de proteína para el mantenimiento y producción de los animales. El objetivo de este trabajo fue determinar las fracciones nitrogenadas de Bothriochloa saccharoides, B. pertusa y Dichanthium annulatum comunes en el trópico seco del norte del Tolima, Colombia.
Resumo:
Despite advances in antibiotic therapy, bacterial meningitis (BM) remains with high mortality and morbidity rates in worldwide. One important mechanism associated to sequels during disease is the intense inflammatory response which promotes an oxidative burst and release of reactive oxygen species, consequently leading to cell death. Activation of DNA repair enzymes during oxidative stress has been demonstrated in several neurological disorders. APE1/Ref-1 is a multifunctional protein involved in DNA repair and plays a redox function on transcription factors such as NFkB and AP-1.The aim of this study was assess the role of APE1/Ref-1 on inflammatory response and the possibility of its modulation to reduce the sequels of the disease. Firstly it was performed an assay to measure cytokine in cerebrospinal fluid of patients with BM due to Streptococcus pneumoniae and Neisseriae meningitides. Further, a cellular model of inflammation was used to observe the effect of the inhibition of the endonuclease and redox activity of APE1/Ref-1 on cytokine levels. Additionally, APE1/Ref-1 expression in cortex and hippocampus of rat with MB after vitamin B6 treatment was evaluated. Altogether, results showed a similar profile of cytokines in the cerebrospinal fluid of patients from both pathogens, although IFNy showed higher expression in patients with BM caused by S. pneumoniae. On the other hand, inhibitors of APE1/Ref-1 reduced cytokine levels, mainly TNF-α. Reduction of oxidative stress markers was also observed after introduction of inhibitors in the LPS-stimulated cell. In the animal model, BM increased the expression of the protein APE1/Ref-1, while vitamin B6 promoted reduction. Thereby, this data rise important factors to be considered in pathogenesis of BM, e.g., IFNy can be used as prognostic factor during corticosteroid therapy, APE1/Ref-1 can be an important target to modulate the level of inflammation and VIII oxidative stress, and vitamin B6 seems modulates several proteins related to cell death. So, this study highlights a new understanding on the role of APE1/Ref-1 on the inflammation and the oxidative stress during inflammation condition
Resumo:
Fundamento. La obstrucción intestinal es una de las urgencias quirúrgicas más frecuentes. Su diagnóstico se basa esencialmente en la historia clínica, la exploración física y las pruebas de imagen. El objetivo de este estudio fue analizar el valor diagnóstico de reactantes de fase aguda en en la obstrucción intestinal y discernir su naturaleza benigna versus maligna. Método. Se ha realizado un estudio de cohortes histórico sobre 53 pacientes sometidos a cirugía por obstrucción intestinal y/o cáncer colorrectal no obstructivo. Los pacientes se encuadraron en 3 grupos: grupo 1 (cáncer colorrectal con obstrucción intestinal) (n=23), grupo 2 (obstrucción intestinal benigna) (n=10) y grupo 3 (cáncer de colon no obstructivo) (n= 20). Se determinan los valores plasmáticos iniciales de la proteína C reactiva (PCR) y el enzima lactato deshidrogenasa (LDH). Resultados. La PCR se elevó cuantitativamente más en pacientes con obstrucción intestinal benigna (grupo 2) (p=0,001), mientras que la LDH en el grupo 1 (pacientes con cáncer obstructivo). Los niveles plasmáticos de LDH fueron significativamente mayores en los grupos con obstrucción intestinal (Grupos 1 y 2) que en pacientes sin obstrucción (p<0,001). Niveles plasmáticos de PCR mayores de 11 mg/l y de LDH mayores de 317 U/L mostraron una validez diagnóstica aceptable para diferenciar los pacientes con obstrucción intestinal, con áreas bajo la curva ROC de 80% (IC 95% = 68-92%) y de 86% (IC 95%= 75-96%) respectivamente. Su validez diagnóstica para diferenciar el origen benigno o maligno es menor, con áreas bajo la curva ROC de 56% para niveles de PCR > 24 ng/l (IC 95% = 30-82%) y de 52% (IC 95% = 29-74%) para niveles de LDH > 359 U/L. Conclusión. La determinación de las concentraciones plasmáticas de la PCR y la LDH pueden ayudar al diagnóstico de la obstrucción intestinal y orientar hacia su origen benigno o maligno en los servicios de urgencias.