966 resultados para Human herpesvirus 4


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T cell immune responses to central nervous system-derived and other self-antigens are commonly described in both healthy and autoimmune individuals. However, in the case of the human prion protein (PrP), it has been argued that immunologic tolerance is uncommonly robust. Although development of an effective vaccine for prion disease requires breaking of tolerance to PrP, the extent of immune tolerance to PrP and the identity of immunodominant regions of the protein have not previously been determined in humans. We analyzed PrP T cell epitopes both by using a predictive algorithm and by measuring functional immune responses from healthy donors. Interestingly, clusters of epitopes were focused around the area of the polymorphic residue 129, previously identified as an indicator of susceptibility to prion disease, and in the C-terminal region. Moreover, responses were seen to PrP peptide 121-134 containing methionine at position 129, whereas PrP 121-134 [129V] was not immunogenic. The residue 129 polymorphism was also associated with distinct patterns of cytokine response: PrP 128-141 [129M] inducing IL-4 and IL-6 production, which was not seen in response to PrP 128-141 [129V]. Our data suggest that the immunogenic regions of human PrP lie between residue 107 and the C-terminus and that, like with many other central nervous system antigens, healthy individuals carry responses to PrP within the T cell repertoire and yet do not experience deleterious autoimmune reactions.

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Following several political-psychological approaches, the present research analyzed whether orientations toward human rights are a function of right-wing authoritarianism (RWA), social dominance orientation (SDO), basic human values in the sense of Schwartz (1992), and political ideology. Three dimensions of human rights attitudes (endorsement, restriction, and enforcement) were differentiated from human rights knowledge and behavior. In a time-lagged Internet survey (N = 479), using structural equation modeling, RWA, universalism and power values, and political ideology (measured at Time 1) differentially predicted dimensions of human rights attitudes (measured at Time 2 five months later). RWA and universalism values also predicted self-reported human rights behavior, with the effects mediated through human rights endorsement. Human rights knowledge also predicted behavior. The psychological roots of positive and negative orientations toward human rights, consequences for human rights education, and the particular role of military enforcement of human rights are discussed.

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The chemokine eotaxin/CCL11 is an important mediator of leukocyte migration, but its effect on inflammatory cytokine signaling has not been explored. In this study, we find that CCL11 induces suppressor of cytokine signaling (SOCS) 1 and SOCS3 expression in murine macrophages, human monocytes, and dendritic cells (DCs). We also discover that CCL11 inhibits GM-CSF-mediated STAT5 activation and IL-4-induced STAT6 activation in a range of hematopoietic cells. This blockade of cytokine signaling by CCL11 results in reduced differentiation and endocytic ability of DCs, implicating CCL11-induced SOCS as mediators of chemotactic inflammatory control. These findings demonstrate cross-talk between chemokine and cytokine responses, suggesting that myeloid cells tracking to the inflammatory site do not differentiate in the presence of this chemokine, revealing another role for SOCS in inflammatory regulation. J. Leukoc. Biol. 85: 289-297; 2009.

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Background: The response rate of aminolaevulinic acid (ALA)-based photodynamic therapy (PDT) in certain subtypes of actinic keratosis (AK), such as hypertrophic and hyperkeratotic lesions, is variable, an effect attributable to a supposed lack of ALA penetration. A detailed and depth-related profile of spatial ALA permeation in AK following drug administration would lead to a greater understanding of concentrations achievable before protoporphyrin IX biosynthesis and subsequent PDT.

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Previous studies have shown that in vitro adenosine enhances histamine release from activated human lung mast cells obtained by enzymic dispersion of lung parenchyma. However, adenosine alone has no effect on histamine release from these cells. Given the evidence for direct activation of mast cells after endobronchial challenge with adenosine and previous studies indicating that mast cells obtained at bronchoalveolar lavage are a better model for asthma studies than those obtained by enzymic dispersion of lung tissue, the histamine-releasing effect of adenosine was examined on lavage mast cells. Bronchoalveolar lavage fluid was obtained from patients attending hospital for routine bronchoscopy (n = 54). Lavage cells were challenged with adenosine or adenosine receptor agonists (20 min, 37 degrees C) and histamine release determined using an automated fluorometric assay. Endogenous adenosine levels were also measured in lavage fluid (n = 9) via an HPLC method. Adenosine alone caused histamine release from ravage mast cells in 37 of 54 patients with a maximal histamine release of 20.56 +/- 2.52% (range 5.2-61 %). The adenosine receptor agonists (R)-N-6-(2-phenylisopropyl)adenosine, 5'-N-ethylcarboxamido-adenosine and CGS21680 also induced histamine release from lavage mast cells. Preincubation of lavage mast cells with the adenosine receptor antagonist xanthine amine congener caused significant inhibition of the response to adenosine (P = 0.007). There was an inverse correlation between endogenous adenosine levels in the lavage fluid and the maximal response to in vitro adenosine challenge of the lavage cells. The findings of the present study indicate a means by which adenosine challenge of the airways can induce bronchoconstriction and support a role for adenosine in the pathophysiology of asthma. The results also suggest that cells obtained from bronchoalveolar ravage fluid may provide the ideal model for the testing of novel, adenosine receptor, targeted therapies for asthma.

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Substance P elicits histamine release from human skin and rodent mast cells. Since neuropeptide-mediated reflexes may be important in asthma, we examined the ability of substance P to stimulate human mast cells obtained at bronchoalveolar lavage (BAL). BAL samples were obtained at routine bronchoscopy from 35 non-preselected patients. Histamine release experiments were performed in a standard manner using substance P and the calcium ionophore A23187. Both substance P (50 μM) and A23187 caused histamine release (median 26.7%, range 6.2–62.8% and 32.1%, 7.7–56.8% respectively) which was significantly greater (P < 0.0001) than the spontaneous release (median 15.6%, range 4.1–33.4%), i.e. that in the absence of any stimulus. Substance P induced histamine release was via an energy dependent process and was blocked by preincubation with antimycin A. A significant correlation was observed between substance P induced release and spontaneous release but was not observed with A23187 induced release. Mast cell counts correlated significantly with substance P induced release but not with spontaneous or A23187 induced release. The substance P induced histamine secretion was elicited at similar concentrations to those used with rodent and human skin mast cells. Asthma is associated with increased numbers of mast cells which have both increased spontaneous and stimulated secretory responses. Thus, in vivo, the bronchoconstrictor action of substance P may in part result from activation of mast cells in the bronchial lumen.

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Cholecystokinin receptor-2 (CCK2R) is a G protein receptor that regulates a number of physiological functions. Activation of CCK2R and/or expression of a constitutively active CCK2R variant may contribute to human diseases, including digestive cancers. Search for antagonists of the CCK2R has been an important challenge during the last few years, leading to discovery of a set of chemically distinct compounds. However, several early-discovered antagonists turned out to be partial agonists. In this context, we carried out pharmacological characterization of six CCK2R antagonists using COS-7 cells expressing the human CCK2R or a CCK2R mutant having a robust constitutive activity on inositol phosphates production, and we investigated the molecular mechanisms which, at a CCK2R binding site, account for these features. Results indicated that three compounds, 3R(+)-N-(2,3-dihydro-1-methyl-2-oxo-5-phenyl-1H-1,4-benzodiazepin-3- yl)-N'-(3-methylphenyl)urea (L365,260), 4-{[2-[[3-(lH-indol-3-yl)-2- methyl-1-oxo-2-[[[1.7.7-trimethyl-bicyclo[2.2.1]hept-2-yl)-oxy]carbonyl]amino] propyl]amino]-1-phenylethyl]amino-4-oxo-[lS-la.2[S*(S*)]4a]} -butanoate N-methyl-D-glucamine (PD135, 158), and (R)-1-naphthalenepropanoic acid, b-[2-[[2-(8-azaspiro-[4.5]dec-8-ylcarbonyl)-4,6-dimethylphenyl]amino]-2- oxoethyl] (CR2945), were partial agonists; one molecule, 1-[(R)-2,3-dihydro-1- (2,3-dihydro-1-(2-methylphenacyl)-2-oxo-5-phenyl-1H-1,4-benzodiazepin-3-yl] -3-(3-methylphenyl)urea (YM022), was a neutral antagonist; and two compounds, N-(+)-[1-(adamant-1-ylmethyl)-2,4-dioxo-5-phenyl2,3,4,5-tetrahydro-1H-1, 5-benzodiazepin-3-yl]-N'-phenylurea (GV150,013X) and ([(N-[methoxy-3 phenyl] N-[N-methyl N-phenyl carbamoylmethyl], carbomoylmethyl)-3 ureido]-3-phenyl)2-propionic acid (RPR101,048), were inverse agonists. Furthermore, target- and pharmacophore-based docking of ligands followed by molecular dynamic simulation experiments resulted in consistent motion of aromatic residues belonging to a network presumably important for activation, thus providing the first structural explanations for the different pharmacological profiles of tested compounds. This study confirms that several referenced so-called antagonists are in fact partial agonists, and because of this undesired activity, we suggest that newly generated molecules should be preferred to efficiently block CCK2R-related physiological effects. Furthermore, data on the structural basis for the different pharmacological features of CCK2R ligands will serve to further clarify CCK2R mechanism of activation. Copyright © 2006 The American Society for Pharmacology and Experimental Therapeutics.

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A radioiodinated ligand, [125I]SB-236636 [(S)-(-)3-[4-[2-[N-(2-benzoxazolyl)-N-methylamino]ethoxy]3-[125I]iodophenyl]2-ethoxy propanoic acid], which is specific for the ? isoform of the peroxisomal proliferator activated receptor (PPAR?), was developed. [125I]SB-236636 binds with high affinity to full-length human recombinant PPAR?1 and to a GST (glutathione S-transferase) fusion protein contg. the ligand binding domain of human PPAR?1 (KD = 70 nM). Using this ligand, the authors characterized binding sites in adipose-derived cells from rat, mouse and humans. In competition expts., rosiglitazone (BRL-49653), a potent antihyperglycemic agent, binds with high affinity to sites in intact adipocytes (IC50 = 12, 4 and 9 nM for rat, 3T3-L1 and human adipocytes, resp.). Binding affinities (IC50) of other thiazolidinediones for the ligand binding domain of PPAR?1 were comparable with those detd. in adipocytes and reflected the rank order of potencies of these agents as stimulants of glucose transport in 3T3-L1 adipocytes and antihyperglycemic agents in vivo: rosiglitazone > pioglitazone > troglitazone. Competition of [125I]SB-236636 binding was stereoselective in that the IC50 value of SB-219994, the (S)-enantiomer of an ?-trifluoroethoxy propanoic acid insulin sensitizer, was 770-fold lower than that of SB-219993 [(R)-enantiomer] at recombinant human PPAR?1. The higher binding affinity of SB-219994 also was evident in intact adipocytes and reflected its 100-fold greater potency as an antidiabetic agent. The results strongly suggest that the high-affinity binding site for [125I]SB-236636 in intact adipocytes is PPAR? and that the pharmacol. of insulin-sensitizer binding in rodent and human adipocytes is very similar and, moreover, predictive of antihyperglycemic activity in vivo.

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As James Scott’s Seeing Like a State attests, forests played a central role in the rise of the modern state, specifically as test spaces for evolving methods of managing state resources at a distance, and as the location for grand state schemes. Together, such ambitions necessitated both the elimination of local understandings of forest management – to be replaced by centrally controlled scientific precision – and a narrowing of state vision. Forests thus began to be conflated with trees (and their timber) alone. All other aspects of the forest, both human and non-human, were ignored. Through the lens of the 18th and early 19th century New Forest in southern England, this paper examines the impact of government attempts to shift the focus of state forests from being remnant medieval hunting spaces to spaces of income generation through the creation of vast sylvicultural plantations. This state scheme not only reworked the relationship between the metropole and the provinces – something effected through systematic surveys and novel bureaucratic procedures – but also dramatically impacted upon the biophysical and cultural geographies of the forest. By equating forest space with trees alone, the British state failed to legislate for the actions of both local commoners and non-human others in resisting their schemes. Indeed, subsequent oppositions proved not only the tenacity of commoners in protecting their livelihoods but also the destructive power of non-human actants, specifically rabbits and mice. The paper concludes that grand state schemes necessarily fail due to their own internal illogic: the narrowing of state vision creates blind spots in which human and non-human lives assert their own visions.

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Theories of dehumanization generally assume a single clear-cut, value-free and non-dilemmatic boundary between the categories 'human' and 'animal'. The present study highlights the relevance of dilemmas involved in drawing that boundary. In six focus groups carried out in Romania and Britain, 42 participants were challenged to think about dilemmas pertaining to animal and human life. Four themes were identified: rational autonomy, sentience, speciesism and maintaining materialist and post-materialist values. Sentience made animals resemble humans, while humans' rational autonomy made them distinctive. Speciesism underlay the human participants' prioritization of their own interests over those of animals, and a conservative consensus that the existing social system could not change supported this speciesism when it was challenged. Romanian participants appealed to Romania's lack of modernity and British participants to Britain's modernity to justify such conservatism. The findings suggest that the human-animal boundary is not essentialized; rather it seems that such boundary is constructed in a dilemmatic and post hoc way. Implications for theories of dehumanization are discussed.

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The suggestion that the general economy of power in our societies is becoming a domain of security was made by Michel Foucault in the late 1970s. This paper takes inspiration from Foucault?s work to interpret human rights as technologies of governmentality, which make possible the safe and secure society. I examine, by way of illustration, the site of the European Union and its use of new modes of governance to regulate rights discourse – in particular via the emergence of a new Fundamental Rights Agency. „Governance? in the EU is constructed in an apolitical way, as a departure from traditional legal and juridical methods of governing. I argue, however, that the features of governance represent technologies of government(ality), a new form of both being governed through rights and of governing rights. The governance feature that this article is most interested in is experts. The article aims to show, first and foremost, how rights operate as technologies of governmentality via a new relation to expertise. Second, it considers the significant implications that this reading of rights has for rights as a regulatory and normalising discourse. Finally, it highlights how the overlap between rights and governance discourses can be problematic because (as the EU model illustrates) governance conceals the power relations of governmentality, allowing, for instance, the unproblematic representation of the EU as an international human rights actor