29 research outputs found

    Isogeometric analysis for fluid shear stress in cancer cells

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    Este trabalho foi financiado pelo Concurso Anual para Projetos de Investigação, Desenvolvimento, Inovação e Criação Artística (IDI&CA) 2018 do Instituto Politécnico de Lisboa. Código de referência IPL/2018/IGACFC_ISELThe microenvironment of the tumor is a key factor regulating tumor cell invasion and metastasis. The effects of physical factors in tumorigenesis is unclear. Shear stress, induced by liquid flow, plays a key role in proliferation, apoptosis, invasion, and metastasis of tumor cells. The mathematical models have the potential to elucidate the metastatic behavior of the cells’ membrane exposed to these microenvironment forces. Due to the shape configuration of the cancer cells, Non-uniform Rational B-splines (NURBS) lines are very adequate to define its geometric model. The Isogeometric Analysis allows a simplified transition of exact CAD models into the analysis avoiding the geometrical discontinuities of the traditional Galerkin traditional techniques. In this work, we use an isogeometric analysis to model the fluid-generated forces that tumor cells are exposed to in the vascular and tumor microenvironments, in the metastatic process. Using information provided by experimental tests in vitro, we present a suite of numerical experiments which indicate, for standard configurations, the metastatic behavior of cells exposed to such forces. The focus of this paper is strictly on geometrical sensitivities to the shear stress’ exhibition for the cell membrane, this being its innovation.info:eu-repo/semantics/publishedVersio

    Brazilian multicenter study of 71 patients with juvenile-onset Takayasu's arteritis: clinical and angiographic features

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    Objective: To describe the clinical and angiographic characteristics of Takayasu's arteritis in Brazilian children and adolescents. Methods: A retrospective data collection was performed in 71 children and adolescents followed in 10 Brazilian reference centers in Pediatric Rheumatology. The evaluation was carried out in three different time points: from onset of symptoms to diagnosis, from the 6th to 12th month of diagnosis, and in the last visit. Results: Of 71 selected patients, 51 (71.8%) were girls. The mean age of onset of symptoms and of time to diagnosis was 9.2 (+/- 4.2) years and 1.2 (+/- 1.4) years, respectively. At the end of the study, 20 patients were in a state of disease activity, 39 in remission and 5 had evolved to death. The most common symptoms in baseline assessment, second evaluation, and final evaluation were, respectively: constitutional, musculoskeletal, and neurological symptoms. A decrease in peripheral pulses was the most frequent cardiovascular signal, and an increase in erythrocyte sedimentation rate was the most frequent laboratory finding in all three evaluation periods. The tuberculin test was positive in 41% of those tested. Stenosis was the most frequent angiographic lesion, abdominal artery was the most affected segment, and angiographic type IV the most frequent. Most (90%) participants were treated with glucocorticoids, 85.9% required another immunosuppressive drug, and 29.6% underwent angioplasty. Conclusion: This is the largest study on juvenile-onset Takayasu arteritis, and a high number of patients under the age of 10 years, with predominance of constitutional symptoms early in the disease, was observed. (C) 2016 Elsevier Editora Ltda. All rights reserved.Univ Fed Sao Paulo, Dept Pediat, Sect Pediat Rheumatol, Sao Paulo, SP, BrazilUniv Sao Paulo, Inst Crianca, Pediat Rheumatol Sect, Sao Paulo, SP, BrazilSanta Casa Misericordia Sao Paulo, Sao Paulo, SP, BrazilUniv Sao Paulo, Sch Med, Ribeirao Preto, SP, BrazilUniv Estado Rio de Janeiro, BR-20550011 Rio De Janeiro, RJ, BrazilUniv Fed Rio de Janeiro, Inst Pediat Martagao Gesteira, Rio De Janeiro, RJ, BrazilUniv Fed Rio de Janeiro, Rheumatol Unit, Rio De Janeiro, RJ, BrazilUniv Fed Pernambuco, Rheumatol Unit, Recife, PE, BrazilUniv Fed Bahia, Salvador, BA, BrazilHosp Pequeno Principe, Curitiba, Parana, BrazilUniv Fed Sao Paulo, Dept Pediat, Sect Pediat Rheumatol, Sao Paulo, SP, BrazilWeb of Scienc

    Dois pares de irmãos com artrite idiopática juvenil (AIJ): relato de casos

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    Relato de casos de ocorrência de Artrite Idiopática Juvenil (AIJ) em dois pares de irmãos acompanhados no serviço de reumatologia pediátrica da Universidade Federal da Bahia. O envolvimento genético na patogênese da AIJ está claro e o risco de recorrência entre irmãos corrobora esta contribuição. Um importante marco dessa descoberta envolve a confirmação da contribuição dos polimorfismos do complexo principal de histocompatibilidade (MHC) na susceptibilidade ao desenvolvimento da AIJ. Apesar de muitos progressos, os inúmeros estudos existentes ainda não são capazes de explicar diversos mecanismos implícitos na patogênese da AIJ

    Ocorrência de doenças autoimunes tireoidianas em pacientes com doenças reumáticas

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    Anormalidades na função tireoidiana e presença de autoanticorpos da tireoide têm sido frequentemente descritas em pacientes com doenças reumatológicas autoimunes, como síndrome de Sjögren, artrite reumatoide, lúpus eritematoso sistêmico e esclerodermia. São limitados os dados sobre prevalência e características clínicas de tireoidite autoimune em outras doenças reumatológicas, tais como febre reumática e lúpus eritematoso sistêmico juvenil. Os autores revisaram as associações de doenças autoimunes endócrinas e reumáticas, avaliando as diversas faixas etárias e condições clínicas. O levantamento bibliográfico foi realizado por meio de busca por artigos científicos indexados em bancos de dados de ciências da saúde em geral, como Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS), Medline/PubMed e Scientific Eletronic Library Online (SciELO). Utilizaram-se os seguintes descritores: "rheumatic autoimmune diseases and autoimmune thyroid diseases", "thyroid disorders and rheumatic diseases", "thyroiditis and rheumatic diseases", "autoimmune diseases and thyroid", e "pediatric rheumatic diseases and autoimmune thyroid diseases". Este estudo mostrou que, apesar de resultados contraditórios na literatura, há maior prevalência da associação entre doenças autoimunes da tireoide e doenças reumáticas, destacando-se a possibilidade de mecanismos patogênicos comuns entre as doenças

    Coexistência de lúpus eritematoso sistêmico e doença falciforme: relato de caso e revisão da literatura

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    Objetivo Relatar um caso de coexistência de lúpus eritematoso sistêmico (LES) e doença falciforme (DF) com revisão da literatura sobre o tema. Metodologia Relato de caso e pesquisa da associação entre LES e DF na literatura, através de artigos científicos nas bases de dados de ciências da saúde, como LILACS, MEDLINE/Pubmed e Scielo, até maio de 2012. Descritores utilizados: 1. anemia falciforme; 2. doença falciforme; 3. lúpus eritematoso sistêmico; 4. hemoglobinopatias. Resultados Os autores descrevem a associação de LES e hemoglobinopatia SS em paciente do sexo feminino, oito anos, apresentando manifestações articulares, hematológicas e neuropsiquiátricas durante a sua evolução clínica. Na literatura são descritos 45 casos de associação entre LES e DF, sendo a maioria em mulheres (78%) adultas (62,2%), apresentando fenótipo SS em 78% dos casos e com manifestações clínicas variadas. Comparando com a nossa paciente, manifestações articulares, hematológicas e neuropsiquiátricas, estiveram presentes em 76%, 36% e 27% dos casos, respectivamente. Conclusões LES e DF são doenças crônicas que apresentam diversos achados clínicos e laboratoriais em comum, implicando em dificuldades diagnósticas e na correta condução terapêutica dessas doenças. A associação entre essas enfermidades não é comum, mas está descrita na literatura, por isso é importante que médicos que cuidam dessas enfermidades estejam atentos para tal possibilidade

    Biological therapy and development of neoplastic disease in patients with juvenile rheumatic disease: a systematic review

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    Abstract Juvenile rheumatic diseases affect the musculoskeletal system and begin before the age of 18. These conditions have varied, identifiable or unknown etiologies, but those of an autoimmune inflammatory nature have been associated with an increased risk of development of cancer, regardless of treatment. This study aims to assess, through a systematic review of the literature according to Prisma (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) quality criteria, the risk of cancer in patients with juvenile rheumatic disease, and its association with biological agents. The criteria described by the Strengthening the Reporting of Observational Studies in Epidemiology initiative were used in order to assess the methodological quality of those individual items selected in this study. We analyzed nine publications, from a total of 251 papers initially selected. There was an increase in cancer risk in the population with juvenile rheumatic disease versus the general population. Most specified cancers were of a lymphoproliferative nature. Seven studies did not specify the treatment or not defined an association between treatment and cancer risk. Only one study has suggested this association; in it, their authors observed high risk in patients diagnosed in the last 20 years, a period of the advent of new therapies. One study found an increased risk in a population not treated with biological agents, suggesting a disease in its natural course, and not an adverse effect of therapy. Studies have shown an increased risk of malignancy associated with juvenile rheumatic disease, and this may be related to disease activity and not specifically to the treatment with biological agents

    Gastrointestinal manifestations as initial presentation of acute leukemias in children and adolescents

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    Objective: this study aimed to determine the prevalence and characteristics of gastrointestinal manifestations on initial clinical presentation of acute leukemias (AL) in childhood. Material and methods: this is a retrospective and descriptive study that assessed medical records of 354 patients with AL from January 1995 to December 2004. Results: acute lymphoid leukemia (ALL) was diagnosed in 273 (77.1%) patients and acute non-lymphocytic leukemia (AML) in 81 (22.9%). There were 210 males (59.4%) and 144 females (40.6%). The most common presenting features were: abdominal pain (19.5% in ALL and 11.8% in AML), nausea and vomiting (14.9 in ALL and 14% in AML), abdominal distention (18.5 in ALL and 8.6% in AML; p 0.024), constipation (5% in ALL and 6.5% in AML), diarrhea (3.6% in ALL and 11.8% in AML; p 0.03%), and gastrointestinal bleeding (7.9% in ALL and 9.7% in AML). Ultrasound scanning was made in 61.1% and hepatomegaly was found on 33.6% and esplenomegaly on 28.5% of the patients with AL. Seventy-seven (21.7%) and 15 (4.2%) patients received nonsteroidal anti-inflammatory drugs and glucocorticoids before the diagnostic of AL. An association is well-defined between abdominal symptoms like nausea, vomiting and pain and use of this therapy but this association did not occurred clearly in this study. Conclusions: gastrointestinal symptoms are not very well-documented as initial manifestation of leukemia in children and should be considered on the differential diagnosis of gastrointestinal symptoms of unknown etiology in children

    Un caso de afectación cutánea severa en la presentación clínica inicial de una dermatomiositis juvenil

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    La dermatomiositis juvenil es una colagenopatía que afecta a niños y adolescentes, princi-palmente entre las edades de 4 y 16 años. Sus principales manifestaciones clínicas son la debilidad simétrica de músculos proximales, enzimas musculares elevadas y la presencia de lesiones cutáneas, como el heliotropo y las pápulas de Gottron. Aquí describimos un caso de dermatomiositis juvenil con un inicio precoz a los 18 meses de edad, presentando lesiones cutáneas ulcerativas severas y vasculopatía probablemente debido a la afectación gastroin-testinal, que requirió tratamiento inmediato con inmunosupresores
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