815 resultados para 610100 - Defence
Resumo:
The reported effects of different families of fatty acids (FA; SFA, MUFA, n-3 and n-6 PUFA) on human health and the importance of macrophage respiratory burst and cytokine release to immune defence led us to examine the influence of palmitic acid (PA), oleic acid (OA), linoleic acid, arachidonic acid, EPA and DHA on macrophage function. We determined fungicidal activity, reactive oxygen species (ROS) and cytokine production after the treatment of J774 cells with non-toxic concentrations of the FA. PA had a late and discrete stimulating effect on ROS production, which may be associated with the reduced fungicidal activity of the cells after treatment with this FA. OA presented a sustained stimulatory effect on ROS production and increased fungicidal activity of the cells, suggesting that enrichment of diets with OA may be beneficial for pathogen elimination. The effects of PUFA on ROS production were time-and dose-dependently regulated, with no evident differences between n-3 and n-6 PUFA. It was worth noting that most changes induced after stimulation of the cells with lipopolysaccharide were suppressed by the FA. The present results suggest that supplementation of the diet with specific FA, not classes of FA, might enable an improvement in host defence mechanisms or a reduction in adverse immunological reactions.
Resumo:
P>Apoptosis of macrophages infected with pathogenic mycobacteria is an alternative host defence capable of removing the environment supporting bacterial growth. In this work the influence of virulence and bacterial load on apoptosis of alveolar macrophages during the initial phase of infection by Mycobacterium bovis was investigated. BALB/c mice were infected intratracheally with high or low doses of the virulent (ATCC19274) or attenuated (bacillus Calmette-Guerin Moreau) strains of M. bovis. The frequency of macrophage apoptosis, the growth of mycobacteria in macrophages, and the in situ levels of the cytokines tumour necrosis factor-alpha (TNF-alpha), interleukin-10 (IL-10) and IL-12 and of the anti-apoptotic protein Bcl-2 were measured at day 3 and day 7 post-infection. An increase of macrophage apoptosis was observed after infection with both strains but the virulent strain induced less apoptosis than the attenuated strain. On the 3rd day after infection with the virulent strain macrophage apoptosis was reduced in the high-dose group, while on the 7th day post-infection macrophage apoptosis was reduced in the low-dose group. Inhibition of apoptosis was correlated with increased production of IL-10, reduced production of TNF-alpha and increased production of Bcl-2. In addition, the production of IL-12 was reduced at points where the lowest levels of macrophage apoptosis were observed. Our results indicate that virulent mycobacteria are able to modulate macrophage apoptosis to an extent dependent on the intracellular bacterial burden, which benefits its intracellular growth and dissemination to adjacent cells.
Resumo:
The increased incidence of infections caused by the opportunistic pathogen Cryptococcus neoformans, which mainly affects immunocompromised patients but can also infect immunocompetent individuals, has needed additional studies on this micro-organism`s pathogenicity and factors related to virulence, such as enzyme production, for a better understanding of the aetiology of cryptococcosis. The aim of this study was to verify the applicability of non-denaturing PAGE for analysis of laccases by quantification of the amount of melanin pigment produced by clinical and environmental strains of C. neoformans. After incubation of the gel with the substrate L-dopa, strains produced melanin spots of a bright brown to black colour. Quantification of these spots was performed by densitometry analysis and the amount of melanin produced was calculated and compared among the strains. All strains showed laccase activity. Serotype B strains showed a higher melanin intensity than serotype A strains. Over half of the clinical strains (56.2%) showed the lowest melanin intensities, suggesting that melanin production may not be the main virulence factor against host defence. The clinical strain ICB 88 revealed two melanin spots on the gel, indicating the presence of two laccase isoforms. The environmental strains showed the highest values of melanin intensity, which may be related to previous exposure to environmental stress conditions.
Resumo:
Meanings of overweight In societal discourses overweight is defined as a growing individual and a social problem leading to sickness and disability, mental distress, increased use of health care and reduced economic productivity. A strong normative pressure is directed at the overweight but relatively few succeed in reducing their weight. Therefore, the overweight need to manage a double stigma; the overweight body per se and their inability to conform to norms about bodyweight. This article investigates how individuals present their overweight to their social environment. Empirical data was collected as part of an evaluation study of a keep-fit project directed at home-care staff. Qualitative interviews were conducted with 49 participants and 30 of them had either tried or were trying to reduce their weight. The analysis shows that the informants presented a divided self consisting of a biological body, with its own drives, and a mind that is aware of the body and its social meanings. They portrayed their lives as a battle between these two sides. Their presentations of the divided self can be analysed as a defence of their social selves. The overweight can account for the kilos by blaming the biological drives, which leaves the core of themselves – their minds – unblemished. They can express an intention to loose weight and thereby conform to norms about bodyweight. When they fail to loose weight, the responsibility can be attributed to the unruly body.
Resumo:
The theme of family in literature and in popular discourse occurs at times when the family as an institution is under attack. Attacks against the family coupled with defence of the family are viewed as the barometer of people’s satisfaction with the society in which they live. This outpouring of emotion, whether it is in defence of or attacking the family, is the result of the family’s position on the bridge between nature and society – a fortunate (or a detrimental) link between an individual and the units that make up a society. Across the United States and much of the western world, the battle for gay marriage and inclusive civil unions has revealed the fissures in our collective moral view of the family. The conservative concern about the absence of ‘family values’ is magnified by our situation in a world of flux. Inflation, war, terrorist threats, and the depletion of natural resources are but a few examples. When so much is unknown, how do we position ourselves? What anchors us to the past, gives us comfort in the present, and supports us in the future if not the family? Alternatively, what coddles us more in the past, shackles us more to the present, and lulls us more into a fixed conception of the future than the family? My research is not a sociological survey into the family nor does it stake any claims to understanding the present state of the family in society. The study seeks, however, to shed light on the rhetorical uses of the family by analysing two novels that are inextricably concerned with the theory of the family in times of heightened social change. In particular, my research focuses upon the social role and political meaning of the family in Anna Karenina and Jia.