982 resultados para Electrophoretic mobility shift assays


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Cutaneous disseminated lesions caused by Leishmania sp. were found in a pregnant mare (Equus cabalus) from a rural city in the State of rio de Janeiro, Brazil. Before delivering, treatment was undertaken by immunotherapy followed by chemotherapy. Histopatology and serology were performed during treatment, as well as the biochemical characterization of the parasite (L. braziliensis) that was isolated from one of the lesions.

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This paper is concerned with the investigation of the intergenerational mobility of education in several European countries and its changes across birth cohorts (1940-1980) using a new mobility index that considers the total degree of mobility as the weighted sum of mobility with respect to both parents. Moreover, this mobility index enables the analysis of the role of family characteristics as mediating factors in the statistical association between individual and parental education. We find that Nordic countries display lower levels of educational persistence but that the degree of mobility increases over time only in those countries with low initial levels. Moreover, the results suggest that the degree of mobility with respect to fathers and mothers converges to the same level and that family characteristics account for an important part of the statistical association between parental education and children’s schooling; a particular finding is that the most important elements of family characteristics are the family’s socio-economic status and educational assortative mating of the parents.

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The study of social mobility enables us to assess the extent to which a given society is "open". Addressing this issue is particularly crucial in our democratic societies, where it is expected that the place of individuals in society should no longer be determined at birth, but rather by individual quality. The present inquiry investigates this issue in the context of Switzerland, a country characterised by specific institutional settings, notably through the close association its educational system shares with the labour market. Through a detailed empirical analysis based on robust statistical analyses carried out from a unique tailor-made dataset, I demonstrate that Swiss society has not become more open throughout the twentieth century. Although some barriers have lost some salience, Swiss society has overall remained extremely rigid. In particular, because it channels individuals into highly segmented tracks very early on, the Swiss educational system does not attenuate social background differences. Thus, Switzerland is found in a particular configuration where an individual's place in society is highly determined not only by his or her educational attainment, but also by his or her social background. In other words, Switzerland constitutes a sort of "non-meritocratic meritocracy". - L'étude de la mobilité sociale permet d'évaluer dans quelle mesure une société donnée est « ouverte ». S'intéresser à cette question est particulièrement crucial dans nos sociétés démocratiques, où il est attendu que la place des individus ne soit plus déterminée à la naissance, mais plutôt par les qualités individuelles. La présente étude examine cette question dans le cadre de la Suisse, un pays aux caractéristiques institutionnelles spécifiques, particulièrement de part le lien étroit que son système éducatif entretien avec le marché du travail. A travers une analyse empirique détaillée fondée sur des analyses statistiques robustes menées à partir d'un jeu de données unique construit sur-mesure, je démontre que la société suisse n'est pas devenue plus ouverte au cours du 20ème siècle. Même si certaines barrières ont perdu de l'importance, dans son ensemble, la société suisse est restée extrêmement rigide. En particulier, parce qu'il oriente très tôt les individus dans des filières fortement segmentées, le système éducatif suisse n'atténue pas les différences entre milieux sociaux. Ainsi, la Suisse se trouve dans une configuration particulière où, d'une part, la place d'un individu dans la société est hautement déterminée par son niveau d'étude et, d'autre part, par son origine sociale. En d'autres termes, la Suisse apparaît comme une sorte de « méritocratie non-méritocratique ».

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Introduction: Epstein-Barr Virus(EBV) has been repeatedly associatedwith multiple sclerosis (MS). Wehave previously shown that there is ahigh peripheral as well as intrathecalactivation of EBV-, but not cytomegalovirus(CMV)-specific CD8+ Tcells, early in the course of MS,strengthening the link between EBVand MS. However, the trigger of thisincreased EBV-specific CD8+ T cellresponse remains obscure. It could resultfrom a higher EBV viral load. Alternatively,it could be due to an intrinsicallydeficient EBV-specificCTL response, cytotoxic granulesmediated.Thus, we performed anin-depth study of the phenotype of exvivo EBV- and CMV-specific CD8+T cells in MS patients and control patients,assessing their cytotoxic activity.Methods:We analyzed the profileof cytotoxic granules in EBV- andCMV-specific CD8+ T cells in a cohortof 13 early MS patients, 20 lateMS, 30 other neurological diseases(OND) patients and 7 healthy controlsubjects. Ex vivo analysis of EBV- orCMV-specific CD8+ T cells was performedusing HLA class I/tetramercomplexes coupled to CCR7 andCD57 markers in conjunction withperforin, granzymes A, BandKstaining.In a sub-cohort of MS patientsand controls, cytotoxic activity ofEBV- and CMV-specific CD8+ Tcells was investigated using a functionalCFSE CTL assay. Results: UsingHLA Class I tetramers for EBVand CMV, we found that the frequencyof EBV- or CMV-specificCD8+ T cells were similar in all studysubjects. Most of EBV- and CMVspecificCD8+Tcells were highly differentiated(CCR7-) and a variousproportion expressed the exhaustionmarker CD57. MS and OND patientshad increased perforin expression inEBV-specific CD8+ T cells. Most importantly,we found that MS patientswith longer disease duration tended tohave lower CTL cytotoxicity as comparedto earlyMSpatients or controls.Conclusions: Effector EBV-specificCD8+ T cells are increased in earlyMS, however their cytotoxic granuleprofile does not seem to be fully alteredand the cytotoxic activity ofthese cells is normal. However, thecytotoxic activity of CTL decreasedin late MS patients suggesting an exhaustionof EBV-specific CD8+ Tcells possibly due to EBV reactivation.This work was supported by theSwiss National Foundation PP00B3-124893, the Swiss Society for MS,and the Biaggi Foundation to RADP.

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Calomys callosus, Rengger 1830 (Rodentia, Cricetidae), a wild rodent found in Central Brazil, was studied to investigate its susceptibility to Toxoplasma gondii experimental infection and its humoral immune response against this protozoa. The electrophoretic profile of the serum proteins of C. callosus showed that IgG, which shows no affinity to Protein A, has higher cross reactivity with rat IgG than with IgG from other rodents. The susceptibility assay was performed by inoculation groups of animals with various suspensions of T. gondii tachyzoites from 102 to 106 parasites. All animals died between 3 and 9 days after infection and the kinetics of antibody synthesis was determined. Basically, they recognized predominantly the immunodominant antigen SAG-1 (P30). The immunohistochemistry assays revealed that the liver was the most heavily infected organ, followed by the spleen, lungs, intestine, brain and kidneys. It can be concluded that C. callosus is an excellent experimental model for acute phase of Toxoplasma infection

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Electrophoretic studies of multilocus-enzymes (MLEE) and whole-cell protein (SDS-PAGE) were carried out in order to evaluate the parity between different methods for the characterization of five Candida species commonly isolated from oral cavity of humans by numerical taxonomy methods. The obtained data revealed that sodium dodecyl sulfate polyacrylamide gel electrophoresis is more efficient in grouping strains in their respective species while MLEE has much limited resolution in organizing all strains in their respective species-specific clusters. MLEE technique must be regarded for surveys in which just one species of Candida is involved.

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Although Colombia presents an enormous biological diversity, few studies have been conducted on the population genetics of Trypanosoma cruzi. This study was carried out with 23 Colombian stocks of this protozoa analyzed for 13 isoenzymatic loci. The Hardy-Weinberg equilibrium, the genetic diversity and heterogeneity, the genetic relationships and the possible spatial structure of these 23 Colombian stocks of T. cruzi were estimated. The majority of results obtained are in agreement with a clonal population structure. Nevertheless, two aspects expected in a clonal structure were not discovered in the Colombian T. cruzi stocks. There was an absence of given zymodemes over-represented from a geographical point of view and the presumed temporal stabilizing selective phenomena was not observed either in the Colombian stocks sampled several times through the years of the study. Some hypotheses are discussed in order to explain the results found.

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Acute human parvovirus B19 infection is followed by an antibody response to the structural proteins of the viral capsid (VP1 and VP2). We used 80 sera collected from 58 erythema infectiosum and 6 transient aplastic crisis patients to test IgM and IgG antibodies against these two proteins in an immunofluorescence assay (IFA) using Sf9 cells infected with recombinant baculovirus expressing either VP1 or VP2 antigen. Although less sensitive than IgM capture enzyme immunoassay using native antigen (MACEIA), we could detect anti-VP1 or anti-VP2 IgM antibodies by IFA in 49 patients with acute infection (76.6%). Detection of IgG anti-VP1 and anti-VP2 by IFA, however, was as sensitive as IgG detection by indirect enzyme immunoassay. By applying IgG avidity IFA to sera of the 15 IgM IFA negative patients we were able to confirm acute infection in further 12 cases by IFA. Overall, acute infection was confirmed by IFA in 61 (95.3%) of the 64 patients.

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En el nostre projecte, considerem un escenari urbà o interurbà on persones amb dispositius mòbils (smartphones) o vehicles equipats amb interfícies de comunicació, estan interessats en compartir fitxers entre ells o descarregar-los al creuar Punts d’Accés (APs) propers a la carretera. Estudiem la possibilitat d’utilizar la cooperació en les trobades casuals entre nodes per augmentar la velocitat de descàrrega global. Amb aquest objectiu, plantejem algoritmes per a la selecció de quins paquets, per a quins destins i quins transportistes s’escullen en cada moment. Mitjançant extenses simulacions, mostrem com les cooperacions carry&forward dels nodes augmenten significativament la velocitat de descàrrega dels usuaris, i com aquest resultat es manté per a diversos patrons de mobilitat, col•locacions d'AP i càrregues de la xarxa. Per altra banda, aparells com els smartphones, on la targeta de WiFi està encesa contínuament, consumeixen l'energia de la bateria en poques hores. En molts escenaris, una targeta WiFi sempre activa és poc útil, perque sovint no hi ha necessitat de transmissió o recepció. Aquest fet es veu agreujat en les Delay Tolerant Networks (DTN), on els nodes intercanvien dades quan es creuen i en tenen l’oportunitat. Les tècniques de gestió de l’estalvi d’energia permeten extendre la duració de les bateries. El nostre projecte analitza els avantatges i inconvenients que apareixen quan els nodes apaguen períodicament la seva targeta wireless per a estalviar energia en escenaris DTN. Els nostres resultats mostren les condicions en que un node pot desconnectar la bateria sense afectar la probabilitat de contacte amb altres nodes, i les condicions en que aquesta disminueix. Per exemple, es demostra que la vida del node pot ser duplicada mantenint la probabilitat de contacte a 1. I que aquesta disminueix ràpidament en intentar augmentar més la vida útil.

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Loss of T-tubules (TT), sarcolemmal invaginations of cardiomyocytes (CMs), was recently identified as a general heart failure (HF) hallmark. However, whether TT per se or the overall sarcolemma is altered during HF process is still unknown. In this study, we directly examined sarcolemmal surface topography and physical properties using Atomic Force Microscopy (AFM) in living CMs from healthy and failing mice hearts. We confirmed the presence of highly organized crests and hollows along myofilaments in isolated healthy CMs. Sarcolemma topography was tightly correlated with elasticity, with crests stiffer than hollows and related to the presence of few packed subsarcolemmal mitochondria (SSM) as evidenced by electron microscopy. Three days after myocardial infarction (MI), CMs already exhibit an overall sarcolemma disorganization with general loss of crests topography thus becoming smooth and correlating with a decreased elasticity while interfibrillar mitochondria (IFM), myofilaments alignment and TT network were unaltered. End-stage post-ischemic condition (15days post-MI) exacerbates overall sarcolemma disorganization with, in addition to general loss of crest/hollow periodicity, a significant increase of cell surface stiffness. Strikingly, electron microscopy revealed the total depletion of SSM while some IFM heaps could be visualized beneath the membrane. Accordingly, mitochondrial Ca(2+) studies showed a heterogeneous pattern between SSM and IFM in healthy CMs which disappeared in HF. In vitro, formamide-induced sarcolemmal stress on healthy CMs phenocopied post-ischemic kinetics abnormalities and revealed initial SSM death and crest/hollow disorganization followed by IFM later disarray which moved toward the cell surface and structured heaps correlating with TT loss. This study demonstrates that the loss of crest/hollow organization of CM surface in HF occurs early and precedes disruption of the TT network. It also highlights a general stiffness increased of the CM surface most likely related to atypical IFM heaps while SSM died during HF process. Overall, these results indicate that initial sarcolemmal stress leading to SSM death could underlie subsequent TT disarray and HF setting.