915 resultados para Osmotic and ionic regulation
Resumo:
OBJETIVO: Avaliar o efeito da estimulação tátil-cinestésica na evolução do padrão comportamental e clínico de recém-nascidos pré-termos (RNPT) durante o período de internação hospitalar. MÉTODOS: Trinta e dois RNPT, com peso ao nascimento inferior a 2.500 gramas, clinicamente estáveis e destituídos de asfixia perinatal importante foram divididos em 16 bebês do grupo controle (GC) e 16 do experimental (GE). Foram coletados dados da evolução clínica a partir dos registros hospitalares e da avaliação comportamental por meio de filmagens semanais de oito minutos, desde a inclusão do RNPT na amostra até a alta hospitalar. RESULTADOS: Tendência a redução do tempo de internação hospitalar, aumento do ganho de peso diário e predominância de comportamentos auto-organizados (respiração regular, estado de alerta, tônus equilibrado, posturas mistas, movimentação coordenada, movimentos de mão na face, sucção, preensão, apoio) para os RNPT do GE. A análise comparativa das idades pós-conceptuais divididas em intervalos (I - 31 a 33 semanas 6/7; II - 34 a 36 semanas 6/7; e III - 37 a 39 semanas 6/7) ressaltou, no aspecto motor, um tônus equilibrado e movimentação voluntária coordenada para os três períodos, maior permanência em posturas mistas (intervalo I) ou em flexão (intervalo II) e a obtenção de respiração mais regular na faixa etária I do GE. CONCLUSÃO: Destaque da estimulação tátil-cinestésica como método de intervenção durante o período de internação hospitalar, contribuindo para a auto-organização e regulação comportamental de RNPT. Artigo registrado no Australian New Zealand Clinical Trials Registry (ANZCTR) sob o número ACTRN12610000133033.
Resumo:
Phthalocyanines have been used as systemic photosensitizers because of their high affinity towards tumour tissue, and the high rates of reactive oxygen species produced when they are irradiated during photodynamic therapy. However, the topical administration of these compounds is limited by their large size, poor hydrosolubility and ionic character. This study aimed to investigate the iontophoretic delivery of charged zinc phthalocyanine tetrasulfonic acid (ZnPcS(4)) from a hydrophilic gel to different skin layers by means of in-vitro and in-vivo studies. Six hours of passive administration was insufficient for ZnPcS(4) to cross the stratum corneum (SC) and to reach the epidermis and dermis. No positive effect was reached when anodal iontophoresis was performed, showing that the drug-electrode attraction effect was higher than the electro-osmosis contribution at a pH of 5.5. Cathodal iontophoresis, however, was able to transport significant amounts of the drug to the viable epidermis. In addition, the absence of NaCl in the formulation significantly increased (by five-fold) the amount of ZnPcS(4) that crossed the SC and accumulated in the epidermis and dermis. It was possible to visualize the drug accumulation in the follicle openings and in the epidermis, even after SC removal. In-vivo experiments in rat skin showed that these results were maintained in an in-vivo model, even with only 15 min of iontophoresis. In addition, confocal analysis of the treated skin showed a homogeneous distribution of ZnPcS(4) in the viable epidermis after this short period of cathodal iontophoresis. Anti-Cancer Drugs 22:783-793 (C) 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins.
Resumo:
Disease resistance is associated with a plant defense response that involves an integrated set of signal transduction pathways. Changes in the expression patterns of 2.375 selected genes were examined simultaneously by cDNA microarray analysis in Arabidopsis thaliana after inoculation with an incompatible fungal pathogen Alternaria brassicicola or treatment with the defense-related signaling molecules salicylic acid (SA), methyl jasmonate (MJ), or ethylene, Substantial changes (up- and down-regulation) in the steady-state abundance of 705 mRNAs were observed in response to one or more of the treatments, including known and putative defense-related genes and 106 genes with no previously described function or homology, In leaf tissue inoculated with A. brassicicola, the abundance of 168 mRNAs was increased more than 2.5-fold, whereas that of 39 mRNAs was reduced. Similarly, the abundance of 192, 221, and 55 mRNAs was highly (>2.5-fold) increased after treatment with SA, MJ, and ethylene, respectively. Data analysis revealed a surprising level of coordinated defense responses, including 169 mRNAs regulated by multiple treatments/defense pathways. The largest number of genes coinduced (one of four induced genes) and corepressed was found after treatments with SA and MJ. In addition, 50% of the genes induced by ethylene treatment were also induced by MJ treatment. These results indicated the existence of a substantial network of regulatory interactions and coordination occurring during plant defense among the different defense signaling pathways, notably between the salicylate and jasmonate pathways that were previously thought to act in an antagonistic fashion.
Resumo:
A knowledge of the physicochemical properties of inclusion bodies is important for the rational design of potential recovery processes such as flotation and precipitation. In this study, measurement of the size and electrophoretic mobility of protein inclusion bodies and cell debris was undertaken. SDS-PAGE analysis of protein inclusion bodies subjected to different cleaning regimes suggested that electrophoretic mobility provides a qualitative measure of protein inclusion body purity. Electrophoretic mobility as a function of electrolyte type and ionic strength was investigated. The presence of divalent ions produced a stronger effect on electrophoretic mobility compared with monovalent ions. The isoelectric point of cell debris was significantly lower than that for the inclusion bodies. Hence, the contaminating cell debris may be separated from inclusion bodies using flotation by exploiting this difference in isoelectric points. Separation by this method is simple, convenient, and a possible alternative to the conventional route of centrifugation.
Expression of the iron regulatory peptide hepcidin is reduced in patients with chronic liver disease
Resumo:
Disturbances in iron metabolism often accompany liver disease in humans and hepatic iron deposition is a frequent finding. Since the peptide hepcidin, a major regulator of body iron homeostasis, is synthesised in the liver, alterations in hepcidin expression could be responsible for these effects. To investigate this possibility, we studied hepcidin expression in liver biopsies from patients with hepatitis C virus (HCV) infection, non-alcoholic fatty liver disease (NAFLD) and hemochromatosis (HC). Total RNA was extracted from the liver tissue of 24 HCV, 17 NASH and 5 HC patients, and 17 liver transplant donors (controls). The levels of mRNA for hepcidin and several other molecules involved in iron metabolism (DMT1, Dcytb, hephaestin, ferroportin, TfR1, TfR2, HFE and HJV) were examined by ribonuclease protection assay and expressed relative to the housekeeping gene GAPDH. The expression of hepcidin was significantly decreased in HCV and NASH patients relative to control liver (109±16 and 200±44 versus 325±26 respectively; P=0.008 and 0.02). We have previously reported similar findings in patients with HC, and this was confirmed in the current analysis (176±21; P=0.003). In both HCV and NAFLD patients the expression of the iron reductase Dcytb and the transferrin binding regulatory molecule TfR2 was also decreased, while the cellular iron exporter ferroportin showed a significant increase. Levels of the mRNA for the iron oxidase hephaestin were lower in HCV patients alone, while expression of the major transferrin binding molecule TfR1 was decreased only in NAFLD patients. Of particular interest was the finding that the expression of HJV (which is mutated in patients with juvenile HC) was significantly increased in NAFLD patients. No changes were seen in the expression of the iron importer DMT1 or the regulatory molecule HFE. Decreased expression of hepcidin in patients with HCV and NAFLD provides an explanation why iron homeostasis could be perturbed in these disorders. Reduced hepcidin levels would increase intestinal iron absorption and iron release from macrophages, which could contribute to hepatic iron accumulation. This in turn could lead to alterations in the expression of various proteins involved in iron transport and its regulation. Indeed most of the changes in the expression of such molecules observed in this study are consistent with this. However, the mechanisms leading to changes in the expression of hepcidin in these diseases remain to be elucidated.
Resumo:
To identify genes differentially expressed in a strain of the mold Aspergillus nidulans carrying a loss-of-function mutation in palA, a gene in the pH-responsive signal transduction pathway, suppression subtractive hybridization was performed between RNA isolated from the biA1 and biA1 palA1 strains grown under limiting inorganic phosphate at pH 5.0. We have identified several genes upregulated in the biA1 palA1 mutant strain that play important roles in mitotic fidelity, stress responses, enzyme secretion, signal transduction mechanisms, development, genome stability, phosphate sensing, and transcriptional regulation among others. The upregulation of eight of these transcripts was also validated by Northern blot. Moreover, we show that a loss of function mutation in the palA gene drastically reduced the neutral sugar content of the acid phosphatase PacA secreted by the fungus A. nidulans grown at pH 5.0 compared with a control strain.
Resumo:
The management of saltwater crocodiles (Crocodylus porosus) in the Northern Territory is an important component of the State’s wildlife management policy. It encompasses saltwater crocodile control (the removal of problem crocodiles dangerous to humans and livestock), and the regulation of harvesting, farming and ranching of saltwater crocodiles for the production of commercial products. The distribution of saltwater crocodiles and their habitats often extend onto private and communal lands along the coastal belt of the Northern Territory, and therefore are a concern of landholders both Aboriginal and pastoral. This report presents the findings of a study of managers of Northern Territory cattle properties (pastoralists). Their attitudes are surveyed towards saltwater crocodiles on their properties and their views of the Northern Territory Parks and Wildlife Commission’s saltwater crocodile management plan are outlined. This report addresses social, economic and environmental aspects of the issue: pastoralists’ attitudes towards saltwater crocodiles in general, the impact saltwater crocodiles have on their cattle-raising business, their opinions of the Northern Territory Government’s saltwater crocodile plan and its operation, and their views of saltwater crocodile harvesting, its potential as an income earner and its contribution to the conservation of the saltwater crocodile. Opinions of pastoralists about new management schemes such as trophy hunting of saltwater crocodiles are also analysed. A concluding statement ties up the findings of the study and provides a snapshot of the current views of pastoral landholders of saltwater crocodiles and their management in the Northern Territory.
Resumo:
Little is known of the mechanisms whereby the mammalian indifferent gonad develops into a testis or ovary. In XY individuals, Sry, the mammalian testis-determining gene, is expressed in the pre-Sertoli cells, which then differentiate into Sertoli cells. Other cell types, which include the germ cells, the steroidogenic cells and the connective tissue cells, must then be instructed to develop in a male-specific manner. Although some genes involved in sex-determination and differentiation processes have been identified, we know little of how they interact and cooperate to orchestrate the development of a testis or ovary. We have initiated an expression-screening program designed to identify additional genes, known or novel, which play a role in these processes. This approach is based on our belief that many of the genes we seek will be expressed in a sex-specific manner during the period of sex-determination and differentiation. Most of the genes identified previously are transcription factors and so we aim, in particular, to find genes involved in cell-to-cell communication, signal transduction, and transcriptional regulation, downstream of the differentiation of Sertoli cells. We have used a suppression subtractive-hybridization method to generate male- and female-enriched probes and libraries. Clones are validated as being sex-specific in their expression patterns by array screening and in situ hybridization. Here we report on our progress to date and the general applicability of the approach for studies in other systems. J. Exp. Zool. 290:517-522, 2001. (C) 2001 Wiley-Liss, Inc.
Resumo:
Adsorption of one nondissociating and four dissociating aromatic compounds onto three untreated activated carbons from dilute aqueous solutions were investigated. All adsorption experiments were preformed in pH-controlled solutions. The experimental isotherms were analyzed using the homogeneous Langmuir model. The surface chemical properties of the activated carbons were characterized using a combination of water adsorption, X-ray photoemission spectroscopy, and mass titration. These data give rise to a new insight into the adsorption mechanism of aromatic solutes, in their molecular and ionic forms, onto untreated activated carbons. It was found that, for the hydrophilic activated carbons, the dominant adsorption forces were observed to be dipolar interactions when the solutes were in their molecular form whereas dispersive forces, such as pi-pi interactions, were most likely dominant in the case of the basic hydrophobic carbons. However, when the solutes were in their ionic form adsorption occurs in all cases through dispersive forces.
Resumo:
O artigo busca fazer uma relação entre a ocorrência de path-dependence, a natureza expectacional do investimento e as flutuações econômicas, a partir de um referencial pós-keynesiano de análise. Em um ambiente não-ergódico, a fim de que o sistema tenha uma relativa estabilidade no tempo, a regulação econômica requer muito mais do que simples ajustamentos incrementais. Tornam-se necessárias, e possíveis, modificações qualitativas do sistema econômico. Tais modificações são analisadas a partir do conceito de bifurcação.
Resumo:
O objetivo central deste estudo é a análise da perspetiva dos Assistentes Sociais sobre a necessidade/ importância da criação de uma Ordem Profissional e, consequentemente de um Código Deontológico (português) para a profissão. Privilegiou-se a investigação qualitativa, construída a partir da interpretação das narrativas das entrevistas, da pesquisa bibliografia e documental. O carácter qualitativo do trabalho concretiza-se por meio de uma lógica abdutiva, que pretende compreender a realidade através da construção dos seus atores (Blaikie, 2000). Para o efeito construímos duas dimensões de análise: a primeira refere-se à análise e compreensão da necessidade de criação de uma Ordem Profissional e a segunda dimensão integra a análise da opinião dos informantes sobre a necessidade de criação de um código deontológico português. Os resultados obtidos nesta investigação demonstram de forma unânime, a importância da criação de uma Ordem Profissional para a legitimação, representatividade e autorregulação da categoria profissional. Nas razões apontadas para a importância da Ordem surgem, quer justificações que se centram na necessidade de uniformização da prática, demonstrando uma visão mais burocrática e tecnicista da profissão, no qual os métodos se sobrepõem à relação, quer razões de legitimação e de necessidade de representação coletiva junto à classe política, relacionada com uma vertente humanista, no qual os aspetos relacionais e comportamentais devem fazer parte da prática profissional de forma a uma maior adequação dos mecanismos de intervenção no indivíduo. Nas razões apontadas para o insucesso da não criação de uma Ordem Profissional, a maioria realçou motivos internos e externos inerentes à profissão. A questão interna tem a ver com a falta de associativismo e união dos Assistentes Sociais em se mobilizarem por uma causa comum. A questão externa relaciona-se com interesses políticos, bem como a questão coletiva dos profissionais. Os princípios subjacentes a um código deontológico são os inerentes aos direitos humanos e justiça social e de atitudes associadas à profissão.
Resumo:
"Consumidores somos todos nós como impressivamente se expressou John F. Kennedy em 15 de Março de 1962. E diríamos que "consumidores de credito "somos muitos. É neste contexto que assume especial relevância a recente aprovação, no nosso ordenamento jurídico, de nova normativa reguladora do crédito ao consumo. Por outro lado, será de realçar o comando constitucional que prevê a protecção dos consumidores. De facto, prescreve o artigo 60° da Constituição da República Portuguesa que "os consumidores têm direito à qualidade dos bens e serviços consumidos, à formação e à informação, à protecção da saúde, da segurança e dos seus interesses económicos, bem como à reparação dos danos". lmporta, pois, conhecer em rigor as normas que actualmente regem o acesso e a regulação dos contratos de crédito ao consumo, num contexto de harmonização comunitária deste instituto jurídico-económico. Será oportuno, sobretudo, compreender de que forma o diploma que actualmente rege a matéria em questão protege de modo mais vincado a parte considerada economicamente mais débil.
Resumo:
Mestrado em Engenharia Química
Resumo:
As instituições particulares de solidariedade social (IPSS) são entidades constituídas por iniciativa de particulares e sem finalidade lucrativa com o propósito de dar expressão organizada ao dever moral de solidariedade e de justiça entre os indivíduos. Considerando as dificuldades económicas que Portugal atravessa estas instituições assumem um papel fundamental na sociedade de hoje, sendo o mesmo reconhecido por estado e clientes. O capital humano é o elemento central no que concerne aos ativos intangíveis e é formado pelas pessoas que integram a instituição. É essencial analisar a gestão dos recursos humanos das IPSS tendo em conta que estes, alinhados com a direção, são parte fulcral para a instituição atingir os objetivos a que se propõe. Com este estudo pretendemos analisar as práticas de gestão de recursos humanos aplicadas pelas IPSS e para o conseguir utilizamos um questionário diagnóstico, distribuído a uma amostra da população, e analisamos as práticas de uma IPSS através de um estudo de caso. O estudo mostrou que as IPSS aplicam maioritariamente a gestão administrativa de recursos humanos e que a regulamentação das instituições por parte da Segurança Social é um fator importante na tipologia de gestão aplicada. As conclusões baseiam-se na análise do estudo de caso e das respostas ao questionário, pelas IPSS da amostra, razão pela qual a generalização das conclusões deverá ser ponderada.