999 resultados para 485-1


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T-cell proliferative hypo responsiveness, a hallmark of paracoccidioidomycosis immune responses, underlies host`s failure in controlling fungus spread, being reversible with antifungal treatment. The mechanisms leading to this hypoproliferation are not well known. Since costimulatory molecules have been shown to profoundly regulate T-cell immune responses, we investigated the hypothesis that the determinants of the responder versus tolerant state may be the regulated expression of, or signaling by, costimulatory molecules. Expression of CD80, CD86, CD28, CD152, ICOS and PD-1 costimulatory molecules were examined on T-cells and monocytes harvested from stimulated and unstimulated PBMC cultures of active paracoccidioidomycosis patients and healthy individuals cured of past paracoccidioidomycosis. Stimuli were gp43, the immunodominant component of Paracoccidioides brasiliensis, and a Candida antigen. While CD28 expression, critical for optimal T-cell activation, was comparable between patients and controls, CD152, PD-1 and ICOS, which preferentially deliver negative signaling, were overexpressed on patients` stimulated and unstimutated T-cells. PBMC cultures were carried out in presence of the respective blocking antibodies which, however, failed to restore T-cell proliferation. CD80 and CD86 were equally expressed on patients` and controls` monocytes, but overexpressed on patients` T-cells. Blockade with the respective blocking antibodies on day 4 of the culture also did not restore T-cell proliferation, while, on day 0, differentially inhibited Candida and gp43 responses, suggesting that different antigens require different costimulatory pathways for antigen presentation. Our data favors the hypothesis, raised from other foreign antigen models, that prolonged in vivo antigen exposure leads to an adaptive tolerance T-cell state which is hardly reverted in vitro. (C) 2008 Elsevier Inc. All rights reserved.

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Polymorphisms of chemokines and chemokine-receptors genes have been shown to influence the rate of progression to AIDS; however, their influence on response to HAART remains unclear. We investigated the frequency of the SDF-1-3`A, CCR2-64I, CCR5-D32 and CCR5-Promoter-59029-A/G polymorphisms in Brazilian HIV-1-infected and uninfected individuals and their influence on CD4+ T-cell evolution HIV-1 infected individuals before and during HAART. Polymorphism detection was done in a transversal study of 200 HIV-1-infected and 82 uninfected individuals. The rate of CD4+ T cell increase or decrease was studied in a cohort of 155 HIV-1 infected individuals on pre and post-HAART. Polymorphisms were determined by PCR associated with RFLP. The rate of CD4+ T-cell decline or increase was also determined. HIV-1 infected and uninfected subjects showed, respectively, frequencies of 0.193 and 0.220 for SDF-1-3`A, of 0.140 and 0.110 for CCR2-V64I, of 0.038 and 0.055 for CCR5-D32, and of 0.442 and 0.390 for CCR5-P-59029-A/G. HIV-1-infected subjects carrying one, two or three of these four polymorphisms showed better CD4+ T-cell recovery than HIV-1-infected subjects carrying the four wild-type alleles (+2.7, +1.6, +3.5, and -0.9 lymphocytes/mu l/month, respectively). Regression logistic analysis showed that the CCR5-D32/CCR2-V64I association was predictor of positive CD4+ T cell slope after HAART. The distribution of polymorphisms did not differ between HIV-1-infected and uninfected individuals, but differed from more homogenous ethnic groups probably reflecting the miscegenation of the Brazilian population. We add further evidence of the role of these polymorphisms by showing that the CD4 gain was influenced by carriage of one or more of the polymorphisms studied here. These results highlight the possibility that these genetic traits can be useful to identify patients at risk for faster progression to AIDS or therapeutic failure.

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Background: Epidermodysplasia verruciformis (EV) is a rare genodermatosis with susceptibility to human papillomavirus (HPV) infection, and high risk of skin cancer considered a model of viral oncogenesis. Methods: Fifteen cases of EV plane wart (PW)-type lesions (EV) and 14 cases of PW in healthy individuals were subjected to immunohistochemical technique for cytokeratins (K) 1, 10, 14, 16, 4, involucrin, filaggrin and e-cadherin. Results: K1/10 showed retarded or negative expression in EV, being substituted by K14. Expression of K14 occurred in the basal and suprabasal layers in both groups, but in EV, its expression was observed up to the more superficial layers. Both groups showed positivity for K16 and K4, involucrin expression in lower levels of the spinous layer and unaltered filaggrin expression. E-cadherin expression was diminished at the koilocytotic foci of both lesions, more superficially in EV. Conclusion: Infection by HPV may alter the differentiation status of the epidermis, leading to a major expression of K14, delayed or absent expression of K1/10 and earlier involucrin expression, especially in EV. It also stimulates the expression of K16 and K4. Filaggrin expression is not altered, and e-cadherin is diminished in superficial koilocytotic cells` foci in EV.

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Fogo selvagern (FS) and pemphigus foliaceus (PF) possess pathogenic IgG anti-desmoglein 1-(Dsg1) autoantibodies. Although PF occurs sporadically, FS is endemic in Limao Verde (LV), Brazil (3.4% prevalence). IgM anti-Dsg1 were detected in 58% FS LV patients (n=31), 19% of FS patients from Hospital-Campo Grande (n=57), 19% from Hospital-Goiania (n=42), 12% from Hospital-Sao Paulo (n=56), 10% of PF patients from United States (n=20), and 0% of PF patients from Japan (n=20). Pemphigus vulgaris (n=40, USA and Japan), bullous pemphigoid (n=40, USA), and healthy donors (n=55, USA) showed negligible percentages of positive sera. High percentages of positive IgM anti-Dsg1 were found in healthy donors from four rural Amerindian populations (42% of 243) as compared with urban donors (14% of 81; P<0.001). More than 50% of healthy donors from LV (n=99, age 5-20 years) possess IgM anti-Dsg1 across ages, whereas IgG-anti-Dsg1 was detected in 2.9% (age 5-10 years), 7.3% (age 11-15 years), and 29% of donors above age 16. IgM anti-Dsg1 epitopes are Ca2+ and carbohydrate-independent. We propose that IgM anti-Dsg1 are common in FS patients in their native environment and uncommon in other pemphigus phenotypes and in FS patients who migrate to urban hospitals. Recurrent environmental antigenic exposure may lead to IgM and IgG responses that trigger TS.

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Bazex - Dupre - Christol syndrome is a rare genodermatosis with cancer predisposition, characterized by follicular atrophoderma, multiple milia, congenital hypotrichosis, hypohidrosis and basal cell malformations that include nevoid basal cell carcinomas of early onset. We present two patients with this syndrome, a 1-year-old boy with diffuse scalp and eyebrows alopecia, milia papules on the face, ears, trunk, and limbs. Hypohidrosis was observed on his trunk and head. His 16-year-old mother had identical changes since childhood, with hair fragility, and multiple atrophic ""ice pick"" follicular depressions on the dorsa of her hands. She also had a basal cell carcinoma on her face. Microscopic examination of hairs from the mother revealed abnormalities such as diameter irregularities, broken shafts, trichorrexis nodosa and pili bifurcatti. Pili bifurcatti is an uncommon hair shaft dysplasia that has not before been observed in Bazex - Dupre - Christol syndrome.

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Background. The formation and measurement of self-concept were the foci of this research. Aims. The study aimed to investigate the influence of achievement on academic self-concept and to compare the Perception of Ability Scale for Students (PASS, Boersma & Chapman, 1992) with the Self-Description Questionnaire-1 (SDQ-1, Marsh, 1988). Sample. The participants were 479 grade 5 (mean age 126.6 months) coeducational Australian students, located in 18 schools. Method. An intra-class research design was used to investigate the influence of frame-of-reference on self-concept development. Results. As students' academic scores rose above their class mean their self-concepts increased and as students' academic scores fell below their class mean their self-concepts decreased. Students' difference from class mean predicted their self-concept scores. This finding was consistently shown across the reading, spelling, and mathematics domains using test and teaching rating data. A comparison between the PASS and the SDQ-1 demonstrated concurrent validity across self-concept domains. Conclusion. The findings support the notions that the social environment is a significant agent that influences self-concept, and that teacher ratings and standardised tests of achievement and the PASS and the SDQ-1 are valid measures for self-concept research.

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For all m greater than or equal to 3 the edges of complete graph on 2m + 1 vertices can he partitioned into m 2m-cycles and an m-cycle.

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The reaction of the bis(1,2-diamine) copper(II) complexes of racemic propane-1,2-diamine (pn) and 2-methylpropane-1,2-diamine (dmen) with formaldehyde and nitroethane in methanol under basic conditions yields minor macrocyclic condensation products in addition to the major acyclic products. Where C-pendant methyl groups on the pair of coordinated diamines are in cis dispositions, the first -NH-CH2-C(CH3)(NO2)-CH2-NH- ring formation occurs at amine pairs distant from these C-methyl substituents, and further reaction to yield a macrocycle is not observed. However, where the C-methyl substituents are in trans dispositions, the chemistry proceeds to yield the macrocycle. Commencing with pn, trans-(6,13-diammonio-2,6,9,13-tetramethyl-1,4,7,10-tetraazacyclotetradecane)copper(II) perchlorate formed and crystallized in the space group P2(1)/n, with a 9.782(2), b 9.2794(6), c 17.017(4) Angstrom, beta 103.24(1)degrees. The copper ion is found in a square-planar environment, with the two methyl groups of the pn residues and the pairs of introduced pendant groups all in trans arrangements.

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We previously generated a panel of T helper cell 1 (Th1) clones specific for an encephalitogenic peptide of myelin proteolipid protein (PLP) peptide 139-151 (HSLGKWLGHPDKF) that induces experimental autoimmune encephalomyelitis (EAE) upon adoptive transfer. In spite of the differences in their T cell receptor (TCR) gene usage, all these Th1 clones required W144 as the primary and most critical TCR contact residue for the activation. In this study, we determined the TCR contact residues of a panel of Th2/Th0 clones specific for the PLP peptide 139-151 generated either by immunization with the PLP 139-151 peptide with anti-B7-1 antibody or by immunization with an altered peptide Q144. Using alanine-substituted peptide analogues of the native PLP peptide, we show that the Th2 clones have shifted their primary contact residue to the NH2-terminal end of the peptide. These Th2 cells do not show any dependence on the W144, but show a critical requirement for L141/G142 as their major TCR contact residue. Thus, in contrast with the Th1 clones that did not proliferate to A144-substituted peptide, the Th2 clones tolerated a substitution at position 144 and proliferated to A144 peptide. This alternative A144 reactive repertoire appears to have a critical role in the regulation of autoimmune response to PLP 139-151 because preimmunization with A144 to expand the L141/G142-reactive repertoire protects mice from developing EAE induced with the native PLP 139-151 peptide. These data suggest that a balance between two different T cell repertoires specific for same autoantigenic epitope can determine disease phenotype, i.e., resistance or susceptibility to an autoimmune disease.

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Conotoxins are small, cysteine-rich peptides isolated from the venom of Conus spp. of predatory marine snails, which selectively target specific receptors and ion channels critical to the functioning of the neuromuscular system. alpha-Conotoxins PnIA and PnIB are both 16-residue peptides (differing in sequence at only two positions) isolated from the molluscivorous snail Conus pennaceus. In contrast to the muscle-selective alpha-conotoxin GI from Conus geographus, PnIA and PnIB block the neuronal nicotinic acetylcholine receptor (nAChR). Here, we describe the crystal structure of PnIB, solved at a resolution of 1.1 Angstrom and phased using the Shake-and-Bake direct methods program. PnIB crystals are orthorhombic and belong to the space group P2(1)2(1)2(1) with the following unit cell dimensions: a = 14.6 Angstrom, b = 26.1 Angstrom, and c = 29.2 Angstrom. The final refined structure of alpha-conotoxin PnIB includes all 16 residues plus 23 solvent molecules and has an overall R-factor of 14.7% (R-free of 15.9%). The crystal structures of the alpha-conotoxins PnIB and PnIA are solved from different crystal forms, with different solvent contents. Comparison of the structures reveals them to be very similar, showing that the unique backbone and disulfide architecture is not strongly influenced by crystal lattice constraints or solvent interactions. This finding supports the notion that this structural scaffold is a rigid support for the presentation of important functional groups. The structures of PnIB and PnIA differ in their shape and surface charge distribution from that of GI.

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The suprathermal particles, electrons and protons, coming from the magnetosphere and precipitating into the high-latitude atmosphere are an energy source of the Earth's ionosphere. They interact with ambient thermal gas through inelastic and elastic collisions. The physical quantities perturbed by these precipitations, such as the heating rate, the electron production rate, or the emission intensities, can be provided in solving the kinetic stationary Boltzmann equation. This equation yields particle fluxes as a function of altitude, energy, and pitch angle. While this equation has been solved through different ways for the electron transport and fully tested, the proton transport is more complicated. Because of charge-changing reactions, the latter is a set of two-coupled transport equations that must be solved: one for protons and the other for H atoms. We present here a new approach that solves the multistream proton/hydrogen transport equations encompassing the collision angular redistributions and the magnetic mirroring effect. In order to validate our model we discuss the energy conservation and we compare with another model under the same inputs and with rocket observations. The influence of the angular redistributions is discussed in a forthcoming paper.

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Obesity can negatively affect pulmonary function tests, with or without clinical symptoms, but the impact of bariatric weight loss is still debated. Aiming to document such profile in a consecutive homogeneous population, a prospective cohort study was undertaken. Sixty-one patients (100% females, age 40 +/- 8 years, BMI 49 +/- 5 kg/m(2) and without respiratory disease) were enrolled. Spirometric analysis was carried out to compare preoperative respiratory pattern with outcome after 6 and 12 months. Variables included vital capacity (VC), expiratory reserve volume (ERV), forced expiratory volume (1 s) (FEV1), FEV1/FVC ratio and maximum voluntary ventilation (MVV). Correlation of results with weight loss was examined. The following initial variables exhibited significant difference when compared to the 12-month postoperative control: FVC (P = 0.0308), FEV1/FVC (P = 0.1998), MVV (P = 0.0004) and ERV (P = 0.2124). Recovery of FVC and FEV1/FVC occurred earlier by 6 months. The most seriously depressed preoperative finding was ERV, which even after 1 year still remained inadequate. (1) Pulmonary limitations were diagnosed in approximately one third of the population. (2) Changes were demonstrated for FVC, FEV1/FVC, ERV and MVV. (3) FEV1 and FEV1/FVC were acceptable due to the absence of an obstructive pattern. (4) Two variables increased by 6 months (FEV1/FVC and ERV), whereas recovery for others was confirmed after 1 year. (5) The only exception was ERV which continued below the acceptable range.

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The production of Long-R-3-IGF-1 (an IGF-1 fusion analog) by constant-rate, fed-batch fermentation of Escherichia coli yielded 2.6 g fusion protein/L, corresponding to an actual IGF-1 concentration of 2.2 g/L. A novel strategy employing three distinct feeding stages was developed which raised product concentration to 4.3 g/L (3.6 g/L of IGF-1) while minimising glucose and acetate accumulation. This improved productivity was not accompanied by an increase in inclusion body size.

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Caring for someone with dementia at home is a difficult task. Support services call do much to assist carers. However, ill rural areas these may not be readily available or accessible. This paper reports on a qualitative study ill which a group of carers living in a rural community participated in a focus group and interviews. Issues explored included the carers' experiences of caring, and the effects of rural life on this, Through content analysis of the data, it was found that these carers faced many challenges but were also able to access a number of supports, particularly in terms of family and the local community.

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The aim of the present work was to assess the role of monocarboxylate transporters (MCTs), namely MCT1 and MCT4 as well as MCT/CD147 co-expression in gastric tissues and evaluate their clinico-pathological significance in gastric carcinoma. For that, we analysed the immunohistochemical expression of MCT1, MCT4 and CD147, in a large series of gastric samples, including non-neoplastic, tumour and metastatic tissues. A significant decrease in MCT4 plasma membrane expression was observed from non-neoplastic to gastric primary malignant tissues and to lymph-node metastasis and both MCT1 and MCT4 correlated with CD147. Importantly, both MCT4 and CD147 were more frequently expressed in Lauren`s intestinal-type tumours and MCT1/CD147 co-expression was associated with advanced gastric carcinoma, Lauren`s intestinal type, TNM staging and lymph-node metastasis. Our results showed that the prognostic value of CD147 was associated with MCTI co-expression in gastric cancer cells, supporting the view that CD147 plasma membrane activity is dependent on MCT co-expression. (C) 2009 Elsevier Ltd. All rights reserved.