963 resultados para algebraic immunity


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Retinoblastoma (RB), a malignant tumour of the eye arising from developing retina, is the most frequent primary intraocular malignancy of childhood. Its primary management with chemotherapy involves combination regimen of etoposide, vincristine and carboplatin and intra vitreal chemotherapy using melphalan when vitreous seeds develop. Radiotherapy is another effective mode in treating RB. We recently explored the notion if radiotherapy in RB can be mediated via Sodium Iodide Symporter (NIS), an intrinsic membrane glycoprotein which is a key regulator of iodide access to thyroid gland. Its expression has been exploited successfully for diagnostic imaging and molecular radionuclide-based therapy of thyroid cancer. We determined that NIS is expressed endogenously in RB tumour tissues, and in retinoblastoma cell lines Y79 and Weri-Rb-1, and therefore made an attempt to enhance the endogenously low expression of NIS protein in both Y79 and Weri-Rb-1 cells. Here we report about the potential of bovine lactoferrin (bLf) which is a known chemo preventive and emerging safe anti-cancer bio drug, as well as a natural transcriptional activator of genes, to enhance the endogenous expression of NIS in Y79 and Weri-Rb-1 cells. Real time PCR revealed that both cell lines express mRNA of lactoferrin receptors while flow cytometry and confocal microscopy showed the cells efficiently internalize bLf which upregulates NIS expression. These findings highlight an important step that could be taken towards the development of less harmful approaches for the treatment of RB by employing natural supplement bLf (with its clinically proven safe profile), and warrants further studies in future, focussing on enhancing NIS expression in RB cells and NIS functional assays in these cells.

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This study investigated in-vivo cell-mediated immune (CMI) responses in elite swimmers over a 5-month training season, to assess the impact of intense training on changes in T-lymphocyte function. The CMI Multitest was performed early in the season after a period of rest, during peak high-intensity training, and late in the season during the precompetition taper period. The CMI tests were performed at rest prior to a morning training session. There were no significant differences between the swimmers and a control group for any of the seven CMI antigen responses at any of the test points during the season. In the swimmers, there were no significant differences in the number of positive responses to the CMI antigens between the three test points (Friedman's test = 9.6364, p = 0.47) and no significant differences for the CMI cumulative scores (Friedman's test = 11.98, p = 0.29) at each test point. There was no consistent pattern for changes in CMI cumulative scores for individual swimmers over the training season. The findings of this study indicate that, despite reported transient T-lymphocyte immunosuppression immediately after intense exercise, probably associated with acute redistribution and temporary pooling of blood T cell subsets in extremities, the T-lymphocyte function involved in CMI responses is not compromised by extended periods of training at an elite level.

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The objective of this study was to evaluate the methodology to establish the hemolytic activity of alternative complement pathway as an indicator of the innate immunity in Brazilian fish pacu (Piaractus mesopotamicus), in addition to verifying the influence of β-glucan as an immunostimulant. Fish were fed with diets containing 0, 0.1 and 1% β-glucan, during seven days, and then inoculated with Aeromonas hydrophila. Seven days after the challenge, they were bled for serum extraction. The methodology consisted of a kinetic assay that allows calculating the required time for serum proteins of the complement to promote 50% lysis of a rabbit red blood cell suspension. The method developed in mammals was successfully applied for pacu and determined that the hemolytic activity of the proteins of the complement system (alternative pathway) increased after the pathogen challenge, but was not influenced by the β-glucan treatment.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Foram avaliados dezesseis doentes portadores de pênfigo foliáceo endêmico, dez com a forma localizada da doença (Grupo G1) e seis com a forma disseminada (Grupo G2), com os objetivos de correlacionar o quadro clínico e laboratorial desses pacientes com o perfil imunológico dos mesmos, e verificar a relação dos títulos dos anticorpos antiepiderme circulantes, identificados pela imunofluorescência indireta, com intensidade da lesão e com a evolução das lesões em tratamento. Foram realizados: hemograma completo, quantificação de subpopulação de células mononucleares por anticorpos monoclonais e estudo da transformação blástica de linfócitos e quantificação de anticorpos circulantes por meio da reação de imunofluorescência indireta. Observou-se leucocitose principalmente no grupo G2, diminuição dos valores relativos das subpopulações de linfócitos CD3+ e CD4+ e tendência à diminuição dos valores relativos da subpopulação CD8+ nos doentes (Grupos G1 e G2). Os índices de transformação blástica de linfócitos frente à fitohemaglutinina revelaram níveis mais elevados nos doentes (Grupos G1 + G2), que nos controles. A reação de imunofluorescência indireta foi positiva em 100% dos doentes do grupo G2 e em 80% do grupo G1 A mediana dos valores dos títulos foi maior no grupo G2, quando comparado com o grupo G1. A análise global dos resultados permite concluir que a imunidade celular está preservada, e que existe uma relação entre os títulos de anticorpos obtidos à reação de imunofluorescência indireta e extensão da lesão cutânea.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Malnutrition may be a consequence of energy deficit or micronutrient deficiency. It is considered the most relevant risk factor for illness and death, particularly in developing countries. In this review we described the magnitude of this problem, as well as its direct effect on the immune system and how it results in higher susceptibility to infections. A special emphasis was given to experimental models used to investigate the relationship between undernutrition and immunity. Malnutrition is obviously a challenge that must be addressed to health authorities and the scientific community.

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A comparative approach is potentially useful for understanding the role of mammal innate immunity role in stimulating adaptive immunity as well as the relationship between these two types of immune strategies. Considerable progress has been made in the elucidation of the co-ordinated events involved in plant perception of infection and their mobilisation of defence responses. Although lacking immunoglobulin molecules, circulating cells, and phagocytic processes, plants successfully use pre-formed physical and chemical innate defences, as well as inducible adaptive immune strategies. In the present paper, we review some shared and divergent immune aspects present in both animals and plants. (C) 2002 Elsevier B.V. All rights reserved.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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In this work we present constructions of algebraic lattices in Euclidean space with optimal center density in dimensions 2, 3, 4, 6, 8 and 12, which are rotated versions of the lattices Λn, for n = 2,3,4,6,8 and K12. These algebraic lattices are constructed through twisted canonical homomorphism via ideals of a ring of algebraic integers. Mathematical subject classification: 18B35, 94A15, 20H10.

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In this paper we review some basic relations of algebraic K theory and we formulate them in the language of D-branes. Then we study the relation between the D8-branes wrapped on an orientable, compact manifold W in a massive Type IIA, supergravity background and the M9-branes wrapped on a compact manifold Z in a massive d = 11 supergravity background from the K-theoretic point of view. By interpreting the D8-brane charges as elements of K-0(C(W)) and the (inequivalent classes of) spaces of gauge fields on the M9-branes as the elements of K-0(C(Z) x ((k) over bar*) G) where G is a one-dimensional compact group, a connection between charges and gauge fields is argued to exists. This connection could be realized as a composition map between the corresponding algebraic K theory groups.

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The cosmological constant is shown to have an algebraic meaning: it is essentially an eigenvalue of a Casimir invariant of the Lorentz group acting on the spaces tangent to every spacetime. This is found in the context of de Sitter spacetimes, for which the Einstein equation is a relation between operators. Nevertheless, the result brings, to the foreground the skeleton algebraic structure underlying the geometry of general physical spacetimes. which differ from one another by the fleshening of that structure by different tetrad fields.

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The algebraic matrix hierarchy approach based on affine Lie sl(n) algebras leads to a variety of 1 + 1 soliton equations. By varying the rank of the underlying sl(n) algebra as well as its gradation in the affine setting, one encompasses the set of the soliton equations of the constrained KP hierarchy.The soliton solutions are then obtained as elements of the orbits of the dressing transformations constructed in terms of representations of the vertex operators of the affine sl(n) algebras realized in the unconventional gradations. Such soliton solutions exhibit non-trivial dependence on the KdV (odd) time flows and KP (odd and even) time Bows which distinguishes them From the conventional structure of the Darboux-Backlund-Wronskian solutions of the constrained KP hierarchy.