991 resultados para Orthogonal polynomials in several variables
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RESUMO:Introdução: O conhecimento acerca da prática da Fisioterapia, bem como a influência das características dos indivíduos com Osteoartrose do joelho (OA) no prognóstico dos resultados alcançados com a Fisioterapia, tem sido alvo de estudo em vários países. No entanto em Portugal, estudos desta natureza são escassos ou inexistentes. Objetivo: Este trabalho teve dois principais objetivos: Por um lado pretendeu caracterizar a prática da Fisioterapia e determinar os seus resultados em indivíduos com OA do joelho ao nível da intensidade da dor, incapacidade funcional e perceção global de melhoria; Por outro, identificar fatores preditivos para os resultados de sucesso após a intervenção da Fisioterapia. Metodologia: Trata-se de um estudo de coorte prospetivo com 77 participantes que foram avaliados antes e após a intervenção (8 semanas), com um follow-up de 3 meses. Procedeu-se à caracterização da prática da Fisioterapia quanto às modalidades utilizadas, número de sessões de tratamento e duração do episódio de cuidados. Os resultados obtidos foram medidos após intervenção (8 semanas) e num follow-up (3 meses), através da Escala Numérica da Dor (END), da versão Portuguesa do Questionário Knee Injury and Osteoarthritis Outcome Score (KOOS-PT), e da versão Portuguesa da Patient Global Impression of Change Scale (PGIC-PT). As características sociodemográficas e clínicas foram incluídas como potenciais fatores de prognóstico com base no critério de pontuação ≥5 na PGIC-PT e a análise dos dados foi realizada através do método de regressão logística multivariado no sentido de identificar as associações entre as variáveis na baseline e as variáveis de resultado (p<0.05). Resultados: Os resultados obtidos revelaram que existe uma grande diversidade de modalidades e procedimentos terapêuticos realizados pelos fisioterapeutas no tratamento da OA do joelho (em média 4 modalidades por utente), sendo os exercícios, a eletroterapia e a terapia manual, as intervenções mais frequentemente realizadas. Os resultados da intervenção revelaram uma redução significativa da intensidade da dor e da incapacidade funcional (medida pelas diferentes dimensões da KOOS-PT) às 8 semanas e aos 3 meses (p=0,001). A probabilidade de obter bons resultados na percepção de melhoria para realizar actividades da vida diária, está significativamente associada com a pontuação na dimensão KOOS AVD (OR=1,106, 95% IC 1,056-1,159) e com a intensidade da dor, (OR=0,543, 95% IC 0,300-0,983), na baseline. A probabilidade de obter bons resultados na percepção de melhoria relativa à dor, está significativamente associada com a pontuação na dimensão KOOS DOR (OR=1,116, 95% IC 1,030-1,209), e dimensão KOOS ADL (OR=1,123, 95% IC 1,014-1,243), na baseline. Conclusões: Os resultados do presente estudo revelam que a intervenção em Fisioterapia em casos de OA do joelho, apesar de utilizar uma grande diversidade de modalidades terapêuticas, proporciona uma redução significativa dos níveis de dor e incapacidade funcional em utentes com OA do joelho. Os resultados do presente estudo sugerem ainda que o sucesso da intervenção pode ser predito a partir de variáveis clinicas na baseline.------------ABSTRACT:Introduction: The knowledge about the practice of physical therapy, as well as the influence of the characteristics of subjects with knee osteoarthritis (OA) in the prognosis of the results achieved with physiotherapy, have been studied in several countries. However in Portugal, such studies are scarce or nonexistent. Objective: This study had two main aims: on one hand sought to characterize the practice of physical therapy and determine their outcomes in subjects with OA of the knee joint at the level of pain intensity, functional disability and global perception of improvement; Secondly, to identify predictive factors for successful outcomes after the intervention of physiotherapy. Methods: This was a prospective cohort study with 77 participants who were evaluated before and after the intervention (8 weeks), with a follow-up of 3 months. Proceeded to characterize the practice of physical therapy as modalities used, number of treatment sessions and duration of the period of care. The results were measured after intervention (8 weeks) and a follow-up (3 months) by a Numerical Rating Scale (NRS), the Portuguese version of the Knee Injury and Osteoarthritis Questionnaire Outcome Score (KOOS-PT) and the Patient Global Impression of Change Scale- Portuguese Version (PGIC-PT). The sociodemographic and clinical characteristics were included as potential prognostic factors based on scoring criteria≥5 na PGIC-PT and data analysis was performed using the method of multivariate logistic regression to identify associations between variables at baseline and outcome variables (p<0.05). Results: The results revealed that there is a great diversity of modalities and therapeutic procedures performed by physiotherapists in the treatment of knee OA (average 4 per user modes), with exercises, electrotherapy and manual therapy interventions most frequently performed. The results of intervention showed a significant reduction in the severity of pain and functional disability (measured by the different dimensions of the KOOS-PT) at 8 weeks and at 3 months (p = 0.001). The probability of getting good results in the perception of improvement to perform activities of daily living, is significantly associated with scores on the dimension KOOS ADL (OR=1,106, 95% CI 1,056-1,159) and the intensity of pain (OR = 0.543, 95% CI 0.300 to 0.983) at baseline. The probability of getting good results in the perception of improvement of the pain is significantly associated with scores on the KOOS PAIN (OR = 1.116, 95% CI 1.030 to 1.209) and KOOS ADL (OR = 1.123, 95% CI 1.014 to 1.243) at the baseline. Conclusions: The results of this study show that Physiotherapy treatment in cases of knee OA, provide a significant reduction of pain and disability among users with knee OA, despite the wide variety of therapeutic modalities. The results of this study also suggest that the success of the intervention can be predicted from clinical variables at baseline.
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INTRODUCTION: Authors describe human schistosomal granuloma in late chronic phase, from the morphological and evolutionary viewpoints. METHODS: The study was based on a histological analysis of two fragments obtained from a surgical biopsy of peritoneum and large intestine of a 42-year-old patient, with a pseudotumoral form mimicking a peritoneal carcinomatosis associated to the schistosomiasis hepatointestinal form. RESULTS: Two hundred and three granulomas were identified in the pseudotumor and 27 in the intestinal biopsy, with similar morphological features, most in the late chronic phase, in fibrotic healing. A new structural classification was suggested for granulomas: zone 1 (internal), 2 (intermediate) and 3 (external). CONCLUSIONS: Regarding granuloma as a whole, we may conclude that fibrosis is likely to be controlled by different and independent mechanisms in the three zones of the granuloma. Lamellar fibrosis in zone 3 seems to be controlled by matrix mesenchymal cells (fibroblasts and myoepithelial cells) and by inflammatory exudate cells (lymphocytes, plasmocytes, neutrophils, eosinophils). Annular fibrosis in zone 2, comprising a dense fibrous connective tissue, with few cells in the advanced phase, would be controlled by epithelioid cells involving zone 1 in recent granulomas. In zone 1, replacing periovular necrosis, an initialy loose and tracery connective neoformation, housing stellate cells or with fusiform nuclei, a dense paucicellular nodular connctive tissue emerges, probably induced by fibroblasts. In several granulomas, one of the zones is missing and granuloma is represented by two of them: Z3 and Z2, Z3 and Z1 or Z2 and Z1 and, ultimately, by a scar.
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INTRODUCTION: The Global Programme to Eliminate Lymphatic Filariasis was launched with the goal of eliminating this disease via the annual mass drug administration (MDA) of a single dose of antifilarial drugs. Adverse drug reactions following MDA are a major factor of poor treatment adherence in several countries. This study assessed the occurrence of adverse drug reactions (ADRs) following the first round of mass treatment in two communities treated with different dosages of diethylcarbamazine (DEC) in the City of Recife, Brazil. METHODS: Population-based cross-sectional surveys were conducted in a random sample of the population living in both communities (Areas I and II). The dose of DEC recommended by the WHO (6mg/kg) was calculated based on the individual's weight-for-age. In Area II, weight differences between the genders were also considered when determining dosage. Data were obtained through interviews conducted in the first 12 to 48h and on the 5th day after MDA during household visits. RESULTS: A total of 487 and 365 individuals were interviewed in Areas I and II, respectively. The prevalence of ADRs in Area I (23.6; 95%CI: 19.1-29.5) was higher than in Area II (16.2; 95%CI:11.9-21.5)(p=0.0078). The prevalence of ADRs among females was higher than in males in Area I (p=0.0021). In Area II, no significant difference between the genders was observed (p=0.1840). Age was not associated with ADRs in either area. CONCLUSIONS: Adjusting MDA dosage schedules according to weight-for-age and sex may be may contribute to reduce the occurrence of adverse drug reactions in the population.
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Living in the digital era, activities that have for centuries acted one way, have now changed and entered the online world, and online grocery shopping is one of them. It is a worldwide phenomenon and is already a significant part of people’s lifestyle in several countries however, in Portugal, it is still in expansion and improvement. Based on the Theory of Planned Behavior, this study allowed to estimate how the perceived risk and shopping orientation counterbalances the convenience offered to consumers. Furthermore, it validated how usability and access to focused promotions can help speed up this adaptation in Portugal
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Introduction Rabies is an important zoonosis that occurs in mammals, with bats acting as Lyssavirus reservoirs in urban, rural and natural areas. Rabies cases in bats have been recorded primarily in urban areas in Northwestern State of São Paulo since 1998. This study investigated the circulation of rabies virus by seeking to identify the virus in the brain in several species of bats in this region and by measuring rabies-virus neutralizing antibody levels in the hematophagous bat Desmodus rotundus. Methods From 2008 to 2012, 1,490 bat brain samples were sent to the Universidade Estadual Paulista (UNESP) Rabies Laboratory in Araçatuba, and 125 serum samples from vampire bats that were captured in this geographical region were analyzed. Results Rabies virus was detected in the brains of 26 (2%) of 1,314 non-hematophagous bats using the fluorescent antibody test (FAT) and the mouse inoculation test (MIT). None of the 176 hematophagous bat samples were positive for rabies virus when a virus detection test was utilized. Out of 125 vampire bat serum samples, 9 (7%) had levels of rabies virus neutralization antibodies (RVNAs) that were higher than 0.5IU/mL; 65% (81/125) had titers between 0.10IU/mL and 0.5IU/mL; and 28% (35/125) were negative for RVNAs using the simplified fluorescent inhibition microtest (SFIMT) in BHK21 cells. The observed positivity rate (1.7%) was higher than the average positivity rate of 1.3% that was previously found in this region. Conclusions The high percentage of vampire bats with neutralizing antibodies suggests that recent rabies virus exposure has occurred, indicating the necessity of surveillance measures in nearby regions that are at risk to avoid diffusion of the rabies virus and possible rabies occurrences.
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Introduction The present study shows the colonization of Aedes mosquitoes in breeding sites specific for Culex quinquefasciatus in neighborhoods in the municipality of Olinda. Methods Samples were collected between May 2011 and June 2012 from breeding sites positive for Cx. quinquefasciatus by using a ladle and manual suction pump. Results Aedes aegypti (0.12%), Aedes albopictus (0.03%), and Cx. quinquefasciatus (99.8%) were found across the breeding sites. Conclusions The presence of Aedes ssp. in several Cx. quinquefasciatus breeding sites with a heavy load of organic material demonstrates the need to review the concepts and methods used for treatment, as the use of specific larvicide for breeding sites of Culex.
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Introduction Hantavirus infections have been described in several regions in Brazil through seroepidemiological studies. Usually, populations are associated with rural and wild environment mainly due to close contact to species of Sigmodontinae rodents, considered hantavirus reservoirs. Methods A retrospective serosurvey was conducted to access the hantavirus seroprevalence in people living in regions affected by bovine vaccinia outbreaks. Results Sera from 53 patients were analyzed and none of them presented anti-hantavirus IgG antibodies. Conclusions This study presents an opportunity to analyze seronegativity despite close and recurrent contact with known hantavirus reservoirs. Aspects of hantavirus and bovine vaccinia emergence are also discussed.
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INTRODUCTION: Aedes albopictus was first detected in Brazil in 1986. This mosquito species presents a major threat to public health because Brazilian populations have shown substantial vector competence for arboviruses such as dengue and chikungunya. METHODS: We updated the records of Ae. albopictus in several States of Brazil, focusing on areas in which its presence had been reported after 2002. RESULTS: Twenty-eight years after its arrival in Brazil, Ae. albopictus has been detected in 24 of 27 States. CONCLUSIONS: The rapid spread of this species and its high vector competence demonstrate the danger of Ae. albopictus in Brazil.
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Chagas disease (ChD), a neglected tropical disease caused by infection with the parasite Trypanosoma cruzi (T. cruzi), remains a serious public health issue in Latin America and is an emerging disease in several non-endemic countries, where knowledge of the condition and experience with its clinical management are limited. Regionally, the disease is the major cause of disability secondary to tropical diseases in young adults. Health-related quality of life (HRQoL) impairment is common in patients with ChD, especially in those with Chagas dilated cardiomyopathy, the most severe manifestation of the disease, which frequently leads to heart failure. The aim of this review was to conduct a literature search for studies that have evaluated the determining factors of HRQoL in ChD patients. We included cross-sectional, case-control, cohort, and experimental studies, as well as clinical trials that evaluated the HRQoL in ChD patients aged 18 to 60 years and are presenting an explicit description of statistical analysis. Using a combination of keywords based on Descriptors in Health Sciences (DeCS) and Medical Subject Headings (MeSH) for searches in PubMed and the Scientific Electronic Library Online (SciELO), 148 studies were found. After exclusions, 12 studies were selected for analysis. Three main findings were extracted from these studies: 1) cardiac involvement is associated with a worse HRQoL in ChD patients; 2) HRQoL is associated with the patients' functional capacity; and 3) simple and inexpensive therapeutic measures are effective for improving HRQoL in ChD patients. Hence, ChD patients' functional capacity, the effectiveness of non-surgical conservative treatment, and cardiac involvement are important determining factors for the HRQoL in ChD patients.
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The aim of this report is to describe the anatomic-pathologic findings from necropsies of 5 drug addicts with titanium pigment in several organs after chronic intravenous injection of crushed propoxyphene hydrochloride tablets. Samples from liver, spleen, lungs, lymph nodes, and bone marrow were obtained, and after being grossly studied, they were submitted to evaluation using common light and polarized microscopy. In all 5 cases, a pigment with characteristics of titanium dioxide was found within tissue samples of the organs studied. Our findings suggest that research concerning titanium pigment within body tissues should be enhanced, considering the potential contribution of this morphologic data to forensic pathology.
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Schizophrenic patients undergoing proton magnetic resonance spectroscopy show alterations in N-acetyl aspartate levels in several brain regions, indicating neuronal dysfunction. The present review focuses on the main proton magnetic resonance spectroscopy studies in the frontal lobe of schizophrenics. A MEDLINE search, from 1991 to March 2004, was carried out using the key-words spectroscopy and schizophrenia and proton and frontal. In addition, articles cited in the reference list of the studies obtained through MEDLINE were included. As a result, 27 articles were selected. The results were inconsistent, 19 papers reporting changes in the N-acetyl aspartate levels, while 8 reported no change. Methodological analysis led to the conclusion that the discrepancy may be due the following factors: (i) number of participants; (ii) variation in the clinical and demographic characteristics of the groups; (iii) little standardization of the acquisition parameters of spectroscopy. Overall, studies that fulfill strict methodological criteria show N-acetyl aspartate decrease in the frontal lobe of male schizophrenics.
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RESUMO: O processo de glicosilação é a modificação pós-traducional de proteínas mais comum e está envolvido em vários processos fisiológicos e patológicos. Especificamente, certos perfis glicosídeos estão correlacionados a estados específicos de diferenciação celular, e podem modular vários eventos celulares, como sinalização celular, migração celular e interações hospedeiro-patogénio. Assim sendo, a glicosilação desempenha um papel crucial na modulação de vários processos imunológicos. No entanto, permanece por esclarecer como as estruturas glicosídicas influenciam a imunidade. Especificamente, algumas estruturas glicosídicas terminais que estão modificadas pela ligação de ácido siálico desempenham um papel importante em várias funções do sistema imune, nomeadamente migração leucocitária em contexto de inflamação e ativação de células imunes. Como tal, este trabalho teve como objectivo investigar como a expressão de certos glicanos influencia componentes importantes da resposta imune inata e adaptativa. Este trabalho está dividido em três componentes principais: 1) A imunidade está amplamente dependente da habilidade das células circulantes migrarem para os tecidos inflamados, sendo que a ligação de leucócitos à Eselectina endotelial é o primeiro passo. Assim, nós analisámos a estrutura e função dos ligandos de E-selectina que são expressos pelas células humanas mononucleares de sangue periférico (PBMCs), fornecendo novos conhecimentos para a compreensão dos intervenientes moleculares que mediam a ligação dos monócitos, células CD4+ e CD8+T e células B ao endotélio vascular. Surpreendentemente, os monócitos apresentaram maior capacidade de ligação à E-selectina comparativamente aos linfócitos. Esta observação pode ser explicada pelo facto de os monócitos humanos expressarem, uniformemente, um vasto reportório de glicoproteínas que exibem afinidade de ligação à E-selectina, nomeadamente: as glicoformas do CD43 (CD43E) e do CD44 (HCELL), em adição à já previamente reportada glicoforma da PSGL-1 (CLA). Consistentemente, a diferente capacidade que as diversas populações linfocitárias apresentam de se ligar à E-selectina, está integralmente relacionada com a sua expressão de glicoproteínas com afinidade de ligação à E-selectina. Enquanto que as células CD4+T apresentam uma elevada reatividade à E-selectina, as células CD8+T e B demonstram pouca ou nenhuma capacidade de ligação à E-selectina. Esta atividade de ligação à E-selectina das células CD4+T é conferida pela expressão de HCELL, em adição às já previamente reportadas CLA e CD43E. As células CD8+ T não expressam HCELL e apenas expressam pequenas quantidades de CLA e CD43E, enquanto que as células B não expressam ligandos de Eselectina. Mais, a exofucosilação da superfície destas células, levou ao dramático aumento da expressão dos ligandos de E-selectina em todos as populações leucocitárias, verificando-se que a criação de certos ligandos de E-selectina está dependente do tipo de célula, após fucosilação. Colectivamente, estes resultados redefinem o nosso conhecimento acerca dos mecanismos moleculares que governam o tráfico das células mononucleares de sangue periférico em contexto de inflamação. 2) A habilidade das células dendríticas (DCs) para extravasarem em locais de inflamação é crucial para o sucesso da terapia com DCs. Assim, analisámos a estrutura e função das moléculas de adesão que mediam a migração transendotelial (TEM) das DCs. Para isso, foram usadas DCs geradas a partir da diferenciação de monócitos (mo-DCS), obtidos quer pelo métodos de separação imuno-magnética de células CD14+ (CD14-S) ou por isolamento por aderência ao plástico (PA-S). Os resultados obtidos indicam que as glicoformas de ligação à Eselectina de PSGL-1, CD43 e CD44 são expressas pelas CD14-S mo-DCs, enquanto que as PA-S mo-DCs expressam apenas CLA. É importante notar que a ligação do CD44 nas mo-DCs, mas não nas PA-S mo-DCs, desencadeia a ativação e consequente adesão da VLA-4 ao endotélio na ausência de um gradiente de quimiocinas. Procedeu-se também à análise dos ligandos E-selectina expressos em mo-DCs geradas a partir de monócitos do sangue do cordão umbilical (UCB) e, inesperadamente, as UCB mo-DCs não expressam qualquer glicoproteína com reatividade à E-selectina. Além disso, a exofucosilação das mo- DCs humanas utilizando uma α(1,3)-fucosiltransferase aumenta significativamente a expressão de HCELL e, portanto, estas células apresentam uma capacidade aumentada para se ligarem à E-selectina em condições de fluxo hemodinâmico. Estes resultados destacam o papel do HCELL no desencadeamento do TEM das CD14-S mo-DCs e sugerem que estratégias para potenciar a expressão de HCELL poderão impulsionar o recrutamento de mo-DCs para locais de inflamação. 3) Outro obstáculo para alcançar o sucesso promissor de vacinas baseadas em DCs é o estabelecimento de abordagens eficientes que poderão melhorar o estado de maturação e apresentação antigénica das DCs. Por conseguinte, foram investigadas abordagens alternativas que podem superar este obstáculo. Através da remoção de ácido siálico de superfície celular das DCs, conseguiu-se induzir a maturação de DC humanas e de ratinhos. Notavelmente, tanto as DCs humanas como as de ratinho, ao serem desialiladas mostraram uma capacidade aumentada para induzir a proliferação de células T, para secretar citocinas Th1 e para induzir a morte específica de células tumorais. Em adição, as DCs desialiladas apresentam uma maior capacidade de apresentação cruzada de antigénios tumorais às células T citotóxicas. Colectivamente, o presente estudo oferece uma visão chave para optimizar a capacidade das DCs em induzir respostas imunitárias anti-tumorais, e indica que o tratamento com sialidase é uma nova tecnologia para melhorar a eficácia e aplicabilidade das vacinas baseadas em DCs. Coletivamente, os nossos resultados demostram como a glicosilação e a sua manipulação podem modular a imunidade. Concretamente, através de uma reação de exofucosilação conseguimos aumentar fortemente a capacidade de os leucócitos extravasarem para os tecidos afectados, enquanto que a remoção dos níveis de ácido siálico da superfície celular das DCs, induz potentes respostas anti-tumorais mediadas por células T citotóxicas. ------------------------------------ ABSTRACT: Glycosylation is the most widely form of protein post-translational modification and is involved in many physiological and pathological processes. Specifically, certain patterns of glycosylation are associated with determined stages of cell differentiation and can modulate processes like cell-signaling and migration and host-pathogen interactions. As such, glycosylation plays a crucial role in the modulation of several immune events. However, how glycans execute this immune-modulation and, therefore, influence immunity is still poorly unknown. Specifically, some terminal sialic acid-modified determinants are known to be involved in several physiological immune processes, including leukocyte trafficking into sites of inflammation and cell immune activation. Therefore, in this work, we sought to investigate more deeply how the expression of these glycosidic structures affects events form both innate and adaptive immune responses. To this end, we divided our work into three main parts: 1) Immunity critically depends on the ability of sentinel circulating cells to infiltrate injured sites, of which leukocyte binding to endothelial E-selectin is the critical first step. Thus, we first analyzed the structure and function of the E-selectin ligands expressed on native human peripheral blood mononuclear cells (PBMCs), providing novel insights into the molecular effectors governing adhesion of circulating monocytes, and of circulating CD4+T, CD8+T and B cells, to vascular endothelium under hemodynamic shear conditions. Strikingly, monocytes show a higher ability to tether and roll on endothelial cells than lymphocyte subsets. This is due to the fact that human circulating monocytes uniformly display a wide repertoire of E-selectin binding glycoproteins, namely the E-selectin-binding glycoforms of CD43 (CD43E) and CD44 (HCELL), in addition to the previously described E-selectin-binding glycoform of PSGL-1 (CLA). In addition, we also observed a differential ability of the different lymphocyte subsets to bind to Eselectin under hemodynamic shear stress conditions, and these differences were highly correlated with their individual expression of E-selectin binding glycoproteins. While CD4+T cells show a robust E-selectin binding ability, CD8+T and B cells show little to no E-selectin reactivity. CD4+T cell potent Eselectin rolling activity is conferred by HCELL expression, in addition to the previously reported E-selectin-binding glycoproteins CD43E and CLA. CD8+T cells display no HCELL and low amounts of CLA and CD43E, whereas B cells lack E-selectin ligand expression. Moreover, enforced exofucosylation of cell surface of these cells noticeably increases expression of functional E-selectin ligands among all leukocytes subsets, with cell type-dependent specificity in the protein scaffolds that are modified. Taken together, these findings redefine our understanding of the molecular mechanisms governing the trafficking patterns of PBMCs that are relevant in the context of acute or chronic inflammatory conditions. 2) The ability of circulating dendritic cells (DCs) to extravasate at inflammatory sites is critical to the success of DC-based therapies. Therefore, we assessed the structure and function of adhesion molecules mediating the transendothelial migration (TEM) of human monocyte derived-DCs (mo-DCs), obtained either by CD14 positive immune-magnetic selection (CD14-S) or by plastic adherence of blood monocytes (PA-S). We report for the first time that the E-selectin binding glycoforms of PSGL-1, CD43 and CD44 are all expressed on CD14-S mo-DCs, in contrast to PA-S mo-DCs that express only CLA. Importantly, CD44 engagement on CD14-S mo-DCs, but not on PA-S mo-DCs, triggers VLA-4-dependent adhesiveness and programs TEM in absence of chemokine gradient. We also analyzed the E-selectin ligands expressed on mo-DCs generated from umbilical cord blood (UCB) monocytes, and unexpectedly, UCB mo-DCs do not express any glycoprotein with E-selectin reactivity. Furthermore, exoglycosylation of human mo-DCs using an α(1,3)-fucosyltransferase significantly increases expression of HCELL, and therefore exofucosylated mo-DCs exhibit an augmented ability to bind to E-selectin under hemodynamic shear stress conditions. These findings highlight a role for HCELL engagement in priming TEM of CD14-S mo-DCs, and suggest that strategies to enforce HCELL expression could boost mo-DC recruitment to inflammatory sites. 3) Another obstacle to achieve the promising success of DC-based vaccines is the establishment of efficient approaches that could successfully enhance maturation and cross-presentation ability of DCs. Therefore, we investigated an alternative approach that can overcome this problem. Through removal of sialic acid content from DC cell surface we are able to elicit maturation of both human and mouse DCs. Notably, desialylated human and murine DCs showed enhanced ability to induce autologous T cell to proliferate, to secrete Th1 cytokines and to kill tumor cells. Moreover, desialylated DCs display enhanced cross-presentation of tumor antigens to cytotoxic CD8+ T cells. Collectively, this study offers key insight to optimize the ability of DCs to boost anti-tumor immune responses, and indicates that the treatment with an exogenous sialidase is a powerful new technology to improve the efficacy and applicability of DC-based vaccines. Overall, our findings show how glycosylation and its manipulation can modulate immunity. Concretely, through an exofucosylation reaction we are able to greatly augment the ability of leukocytes to extravasate into injured tissues, while removal of sialic acid moieties from cell surface of DCs, significantly potentiate their ability to induce anti-tumor cytotoxic T cell-mediate responses.
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In museum studies and history of art, what happens behind the scenes of museums stays relatively unseen and unspoken about. In the arts, generally speaking, what is dismissed as irrelevant (e.g. the realm of practices) is deliberately detached from what is thought to really matter; theory, discourse, content and meaning. Up till recently, backstage activities such as conservation practices are merely discussed among specialists and museum professionals. Only the outcomes of these discussions are sometimes – if at all – explicitly communicated to a larger public. Studies into the practices of contemporary art conservation however show that practices behind the scenes play an important role in the perpetuation of these artworks. What happens behind the scenes in terms of conservation has, in several ways, important effects on the ongoing life of these artworks in a museum context. Conservation practices, I argue, should therefore become a necessary part of museum studies and history of art. How can the working practices of conservators become more visible and transparent to a diversity of audiences, including researchers? And what does this mean in terms of research methodology?
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RESUMO:O processo de glicosilação é a modificação pós-traducional de proteínas mais comum e está envolvido em vários processos fisiológicos e patológicos. Especificamente, certos perfis glicosídeos estão correlacionados a estados específicos de diferenciação celular, e podem modular vários eventos celulares, como sinalização celular, migração celular e interações hospedeiro-patogénio. Assim sendo, a glicosilação desempenha um papel crucial na modulação de vários processos imunológicos. No entanto, permanece por esclarecer como as estruturas glicosídicas influenciam a imunidade. Especificamente, algumas estruturas glicosídicas terminais que estão modificadas pela ligação de ácido siálico desempenham um papel importante em várias funções do sistema imune, nomeadamente migração leucocitária em contexto de inflamação e ativação de células imunes. Como tal, este trabalho teve como objectivo investigar como a expressão de certos glicanos influencia componentes importantes da resposta imune inata e adaptativa. Este trabalho está dividido em três componentes principais: 1) A imunidade está amplamente dependente da habilidade das células circulantes migrarem para os tecidos inflamados, sendo que a ligação de leucócitos à Eselectina endotelial é o primeiro passo. Assim, nós analisámos a estrutura e função dos ligandos de E-selectina que são expressos pelas células humanas mononucleares de sangue periférico (PBMCs), fornecendo novos conhecimentos para a compreensão dos intervenientes moleculares que mediam a ligação dos monócitos, células CD4+ e CD8+T e células B ao endotélio vascular. Surpreendentemente, os monócitos apresentaram maior capacidade de ligação à E-selectina comparativamente aos linfócitos. Esta observação pode ser explicada pelo facto de os monócitos humanos expressarem, uniformemente, um vasto reportório de glicoproteínas que exibem afinidade de ligação à E-selectina, nomeadamente: as glicoformas do CD43 (CD43E) e do CD44 (HCELL), em adição à já previamente reportada glicoforma da PSGL-1 (CLA). Consistentemente, a diferente capacidade que as diversas populações linfocitárias apresentam de se ligar à E-selectina, está integralmente relacionada com a sua expressão de glicoproteínas com afinidade de ligação à E-selectina. Enquanto que as células CD4+T apresentam uma elevada reatividade à E-selectina, as células CD8+T e B demonstram pouca ou nenhuma capacidade de ligação à E-selectina. Esta atividade de ligação à E-selectina das células CD4+T é conferida pela expressão de HCELL, em adição às já previamente reportadas CLA e CD43E. As células CD8+ T não expressam HCELL e apenas expressam pequenas quantidades de CLA e CD43E, enquanto que as células B não expressam ligandos de Eselectina. Mais, a exofucosilação da superfície destas células, levou ao dramático aumento da expressão dos ligandos de E-selectina em todos as populações leucocitárias, verificando-se que a criação de certos ligandos de E-selectina está dependente do tipo de célula, após fucosilação. Colectivamente, estes resultados redefinem o nosso conhecimento acerca dos mecanismos moleculares que governam o tráfico das células mononucleares de sangue periférico em contexto de inflamação. 2) A habilidade das células dendríticas (DCs) para extravasarem em locais de inflamação é crucial para o sucesso da terapia com DCs. Assim, analisámos a estrutura e função das moléculas de adesão que mediam a migração transendotelial (TEM) das DCs. Para isso, foram usadas DCs geradas a partir da diferenciação de monócitos (mo-DCS), obtidos quer pelo métodos de separação imuno-magnética de células CD14+ (CD14-S) ou por isolamento por aderência ao plástico (PA-S). Os resultados obtidos indicam que as glicoformas de ligação à Eselectina de PSGL-1, CD43 e CD44 são expressas pelas CD14-S mo-DCs, enquanto que as PA-S mo-DCs expressam apenas CLA. É importante notar que a ligação do CD44 nas mo-DCs, mas não nas PA-S mo-DCs, desencadeia a ativação e consequente adesão da VLA-4 ao endotélio na ausência de um gradiente de quimiocinas. Procedeu-se também à análise dos ligandos E-selectina expressos em mo-DCs geradas a partir de monócitos do sangue do cordão umbilical (UCB) e, inesperadamente, as UCB mo-DCs não expressam qualquer glicoproteína com reatividade à E-selectina. Além disso, a exofucosilação das mo- DCs humanas utilizando uma α(1,3)-fucosiltransferase aumenta significativamente a expressão de HCELL e, portanto, estas células apresentam uma capacidade aumentada para se ligarem à E-selectina em condições de fluxo hemodinâmico. Estes resultados destacam o papel do HCELL no desencadeamento do TEM das CD14-S mo-DCs e sugerem que estratégias para potenciar a expressão de HCELL poderão impulsionar o recrutamento de mo-DCs para locais de inflamação. 3) Outro obstáculo para alcançar o sucesso promissor de vacinas baseadas em DCs é o estabelecimento de abordagens eficientes que poderão melhorar o estado de maturação e apresentação antigénica das DCs. Por conseguinte, foram investigadas abordagens alternativas que podem superar este obstáculo. Através da remoção de ácido siálico de superfície celular das DCs, conseguiu-se induzir a maturação de DC humanas e de ratinhos. Notavelmente, tanto as DCs humanas como as de ratinho, ao serem desialiladas mostraram uma capacidade aumentada para induzir a proliferação de células T, para secretar citocinas Th1 e para induzir a morte específica de células tumorais. Em adição, as DCs desialiladas apresentam uma maior capacidade de apresentação cruzada de antigénios tumorais às células T citotóxicas. Colectivamente, o presente estudo oferece uma visão chave para optimizar a capacidade das DCs em induzir respostas imunitárias anti-tumorais, e indica que o tratamento com sialidase é uma nova tecnologia para melhorar a eficácia e aplicabilidade das vacinas baseadas em DCs. Coletivamente, os nossos resultados demostram como a glicosilação e a sua manipulação podem modular a imunidade. Concretamente, através de uma reação de exofucosilação conseguimos aumentar fortemente a capacidade de os leucócitos extravasarem para os tecidos afectados, enquanto que a remoção dos níveis de ácido siálico da superfície celular das DCs, induz potentes respostas anti-tumorais mediadas por células T citotóxicas. ---------------------------- ABSTRACT: Glycosylation is the most widely form of protein post-translational modification and is involved in many physiological and pathological processes. Specifically, certain patterns of glycosylation are associated with determined stages of cell differentiation and can modulate processes like cell-signaling and migration and host-pathogen interactions. As such, glycosylation plays a crucial role in the modulation of several immune events. However, how glycans execute this immune-modulation and, therefore, influence immunity is still poorly unknown. Specifically, some terminal sialic acid-modified determinants are known to be involved in several physiological immune processes, including leukocyte trafficking into sites of inflammation and cell immune activation. Therefore, in this work, we sought to investigate more deeply how the expression of these glycosidic structures affects events form both innate and adaptive immune responses. To this end, we divided our work into three main parts: 1) Immunity critically depends on the ability of sentinel circulating cells to infiltrate injured sites, of which leukocyte binding to endothelial E-selectin is the critical first step. Thus, we first analyzed the structure and function of the E-selectin ligands expressed on native human peripheral blood mononuclear cells (PBMCs), providing novel insights into the molecular effectors governing adhesion of circulating monocytes, and of circulating CD4+T, CD8+T and B cells, to vascular endothelium under hemodynamic shear conditions. Strikingly, monocytes show a higher ability to tether and roll on endothelial cells than lymphocyte subsets. This is due to the fact that human circulating monocytes uniformly display a wide repertoire of E-selectin binding glycoproteins, namely the E-selectin-binding glycoforms of CD43 (CD43E) and CD44 (HCELL), in addition to the previously described E-selectin-binding glycoform of PSGL-1 (CLA). In addition, we also observed a differential ability of the different lymphocyte subsets to bind to Eselectin under hemodynamic shear stress conditions, and these differences were highly correlated with their individual expression of E-selectin binding glycoproteins. While CD4+T cells show a robust E-selectin binding ability, CD8+T and B cells show little to no E-selectin reactivity. CD4+T cell potent Eselectin rolling activity is conferred by HCELL expression, in addition to the previously reported E-selectin-binding glycoproteins CD43E and CLA. CD8+T cells display no HCELL and low amounts of CLA and CD43E, whereas B cells lack E-selectin ligand expression. Moreover, enforced exofucosylation of cell surface of these cells noticeably increases expression of functional E-selectin ligands among all leukocytes subsets, with cell type-dependent specificity in the protein scaffolds that are modified. Taken together, these findings redefine our understanding of the molecular mechanisms governing the trafficking patterns of PBMCs that are relevant in the context of acute or chronic inflammatory conditions. 2) The ability of circulating dendritic cells (DCs) to extravasate at inflammatory sites is critical to the success of DC-based therapies. Therefore, we assessed the structure and function of adhesion molecules mediating the transendothelial migration (TEM) of human monocyte derived-DCs (mo-DCs), obtained either by CD14 positive immune-magnetic selection (CD14-S) or by plastic adherence of blood monocytes (PA-S). We report for the first time that the E-selectin binding glycoforms of PSGL-1, CD43 and CD44 are all expressed on CD14-S mo-DCs, in contrast to PA-S mo-DCs that express only CLA. Importantly, CD44 engagement on CD14-S mo-DCs, but not on PA-S mo-DCs, triggers VLA-4-dependent adhesiveness and programs TEM in absence of chemokine gradient. We also analyzed the E-selectin ligands expressed on mo-DCs generated from umbilical cord blood (UCB) monocytes, and unexpectedly, UCB mo-DCs do not express any glycoprotein with E-selectin reactivity. Furthermore, exoglycosylation of human mo-DCs using an α(1,3)-fucosyltransferase significantly increases expression of HCELL, and therefore exofucosylated mo-DCs exhibit an augmented ability to bind to E-selectin under hemodynamic shear stress conditions. These findings highlight a role for HCELL engagement in priming TEM of CD14-S mo-DCs, and suggest that strategies to enforce HCELL expression could boost mo-DC recruitment to inflammatory sites.3) Another obstacle to achieve the promising success of DC-based vaccines is the establishment of efficient approaches that could successfully enhance maturation and cross-presentation ability of DCs. Therefore, we investigated an alternative approach that can overcome this problem. Through removal of sialic acid content from DC cell surface we are able to elicit maturation of both human and mouse DCs. Notably, desialylated human and murine DCs showed enhanced ability to induce autologous T cell to proliferate, to secrete Th1 cytokines and to kill tumor cells. Moreover, desialylated DCs display enhanced cross-presentation of tumor antigens to cytotoxic CD8+ T cells. Collectively, this study offers key insight to optimize the ability of DCs to boost anti-tumor immune responses, and indicates that the treatment with an exogenous sialidase is a powerful new technology to improve the efficacy and applicability of DC-based vaccines. Overall, our findings show how glycosylation and its manipulation can modulate immunity. Concretely, through an exofucosylation reaction we are able to greatly augment the ability of leukocytes to extravasate into injured tissues, while removal of sialic acid moieties from cell surface of DCs, significantly potentiate their ability to induce anti-tumor cytotoxic T cell-mediate responses.
Resumo:
The effects of PMSs on the people’s behaviour represent a high degree of relevance in the context of an organization performance and success. Thus, motivational and behavioural consequences of performance measurements are far from being totally understood (Franco-Santos et al., 2012). This work project (WP) purposes going further regarding the consequences/effects on people’s behaviour of using PMSs in organizations. The researcher conducted 11 interviews to managers during a nine-month internship as a controller in a Portuguese multi-national company. The evidence from this WP suggests that the way how managers understand a PMS determines a lot the way how they behave. Data also supports that PMSs influences in several ways motivation, perceptions, participation and job-related stress of managers.