831 resultados para HLA-E
Infantile epileptic encephalopathy with hypsarrhythmia (infantile spasms/west syndrome) and immunity
Resumo:
West syndrome is a severe epilepsy, occurring in infancy, that comprises epileptic seizures known as spasms, in clusters, and a unique EEG pattern, hypsarrhythmia, with psychomotor regression. Maturation of the brain is a crucial component. The onset is within the first year of life, before 12 months of age. Patients are classified as cryptogenic (10 to 20%), when there are no known or diagnosed previous cerebral insults, and symptomatic (80 to 90%), when associated with pre-existing cerebral damages. The time interval from a brain insult to infantile spasms onset ranged from 6 weeks to 11 months. West syndrome has a time-limited natural evolutive course, usually disappearing by 3 or 4 years of age. In 62% of patients, there are transitions to another age-related epileptic encephalopathies, the Lennox-Gastaut Syndrome and severe epilepsy with multiple independent foci. Spontaneous remission and remission after viral infections may occur. Therapy with ACTH and corticosteroids are the most effective. Reports about intravenous immunoglobulins action deserve attention. There is also immune dysfunction, characterized mainly by anergy, impaired cell-mediated immunity, presence of immature thymocytes in peripheral blood, functional impairment of T lymphocytes induced by plasma inhibitory factors, and altered levels of immunoglobulins. Changes in B lymphocytes frequencies and increased levels of activated B cells have been reported. Sensitized lymphocytes to brain extract were also described. Infectious diseases are frequent and may, sometimes, cause fatal outcomes. Increase of pro-inflamatory cytokines in serum and cerebrospinal fluid of epileptic patients were reported. Association with specific HLA antigens was described by several authors (HLA-DR7, HLA-A7, HLA-DRw52, and HLA-DR5). Auto-antibodies to brain antigens, of several natures (N-methyl-d-aspartate glutamate receptor, gangliosides, brain tissue extract, synaptic membrane, and others), were described in epileptic patients and in epileptic syndromes. Experimental epilepsy studies with anti-brain antibodies demonstrated that epileptiform discharges can be obtained, producing hyperexcitability leading to epilepsy. We speculate that in genetically prone individuals, previous cerebral lesions may sensitize immune system and trigger an autoimmune disease. Antibody to brain antigens may be responsible for impairment of T cell function, due to plasma inhibitory effect and also cause epilepsy in immature brains. © 2008 Bentham Science Publishers Ltd.
Resumo:
Propolis is a beehive product used in traditional medicine due to its biological properties. It shows a complex chemical composition including phenolics, such as cinnamic acid (Ci). The mechanisms of action of propolis have been the subject of research recently; however, the involvement of Ci on propolis activity was not investigated on immune cells. Ci effects were evaluated on human monocytes, assessing the expression of Toll-like receptors (TLRs), HLA-DR, and CD80. Cytokine production (TNF-α and IL-10) and the fungicidal activity of monocytes were evaluated as well. Data showed that Ci downregulated TLR-2, HLA-DR, and CD80 and upregulated TLR-4 expression by human monocytes. High concentrations of Ci inhibited both TNF-α and IL-10 production, whereas the same concentrations induced a higher fungicidal activity against Candida albicans. TNF-α and IL-10 production was decreased by blocking TLR-4, while the fungicidal activity of monocytes was not affected by blocking TLRs. These results suggest that Ci modulated antigen receptors, cytokine production, and the fungicidal activity of human monocytes depending on concentration, and TLR-4 may be involved in its mechanism of action. Ci seemed to be partially involved in propolis activities. © 2013 Bruno José Conti et al.
Resumo:
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Resumo:
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Resumo:
Pós-graduação em Pesquisa e Desenvolvimento (Biotecnologia Médica) - FMB
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Pós-graduação em Ginecologia, Obstetrícia e Mastologia - FMB
Resumo:
Pós-graduação em Doenças Tropicais - FMB
Resumo:
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Resumo:
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Resumo:
Pós-graduação em Genética - IBILCE
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
ABSTRACT: Soroprevalence for Hepatitis C virus is reported as 2.12% in Northern Brazil, with about 50% of the patients exhibiting a sustained virological response (SVR). Aiming to associate polymorphisms in Killer Cell Immunoglobulin-like Receptors (KIR) with chronic hepatitis C and therapy responses we investigated 125 chronic patients and 345 controls. Additionally, 48 ancestry markers were genotyped to control for population stratification. The frequency of the KIR2DL2 and KIR2DL2+HLA-CAsp80 gene and ligand was higher in chronic infected patients than in controls (p < 0.0009, OR = 3.4; p = 0.001, OR = 3.45). In fact, KIR2DL3 is a weaker inhibitor of NK activity than KIR2DL2, which could explain the association of KIR2DL2 with chronic infection. Moreover, KIR2DS2 and KIR2DS2+HLA-CAsp80 (p < 0.0001, OR = 2.51; p = 0.0084, OR = 2.62) and KIR2DS3 (p < 0.0001; OR = 2.57) were associated with chronic infection, independently from KIR2DL2. No differences in ancestry composition were observed between control and patients, even with respect to therapy response groups. The allelic profile KIR2DL2/KIR2DS2/KIR2DS3 was associated with the chronic hepatitis C (p < 0.0001; OR = 3). Furthermore, the patients also showed a higher mean number of activating genes and a lower frequency of the homozygous AA profile, which is likely secondary to the association with non-AA and/or activating genes. In addition, the KIR2DS5 allele was associated with SVR (p = 0.0261; OR = 0.184).The ancestry analysis of samples ruled out any effects of population substructuring and did not evidence interethnic differences in therapy response, as suggested in previous studies.
Resumo:
A hanseníase é uma infecção crônica e granulomatosa da pele e nervos periféricos, que infecta principalmente macrófagos e células de Schwann. A Organização Mundial de Saúde classifica a hanseníase em duas formas polares: multibacilar e paucibacilar, de acordo com o índice baciloscópico e a resposta imune do hospedeiro. As células natural killer (NK) têm um importante papel na infecção, sendo a primeira forma de defesa contra organismos intracelulares. As células NK utilizam muitos tipos de receptores de superfície celular, como os receptores imunoglobulina-símiles de célula NK (KIR), que podem inibir ou ativar a resposta citolítica de NK, através do reconhecimento de moléculas do complexo de histocompatibilidade principal (MHC) de classe I na célula alvo. Nesse estudo caso controle, a presença ou ausência de 15 genes KIR e seus ligantes HLA-C foram investigadas, na intenção de se descrever sua variabilidade genotípica, associação com a hanseníase e sua evolução clínica. A genotipagem do complexo de genes KIR e dos grupos NK1 e NK2 de HLA-C foi feita por PCR-SSP em 105 pacientes e 104 controles. KIR2DL2 e KIR2DL3, na presença do seu ligante HLA-Cw parece predispor à hanseníase (p=0,046; X2= 3,97; OR=1,99; IC 95%= 1,00-3,97). Além disso, a prevalência da hanseníase ao redor do mundo e as freqüências de KIR2DL2 se correlacionaram positivamente. Esse achado, juntamente com a associação entre KIR2DL3 e a tuberculose, descrita por outros autores, sugere que esses genes de receptores inibitórios predispõem à doença. Adicionalmente, o gene KIR2DS2 foi associado com o desenvolvimento da hanseníase paucibacilar (p=0,009; X2= 7,23; OR=3,97; IC 95%= 1,37-9,96), possivelmente modulando o desenvolvimento para a forma mais branda da doença.
Resumo:
O objetivo deste trabalho foi avaliar a potencialidade das sementes de açaí rejeitadas após beneficiamento em Belém – Pará, a fim de ser usada como fonte de biomassa para a produção de energia por gaseificação. Resultados da análise elementar obtidas no LABCAT – UNB em base seca foram obtidas com percentuais de Carbono, 46,06 %, Hidrogênio 6,01 % Oxigênio 43,37 %, Nitrogênio 4,33 % e Enxofre 0,08%. Tais valores entre outros parâmetros obtidos em estudo experimental realizados por Santos 2011 e Cruz, 2010, foram utilizados para realizar uma simulação numérica do processo de gaseificação por meio de um código FORTRAN zero dimensional desenvolvido especificamente para esta finalidade. Variações da influência da razão de equivalência e teor de umidade nas concentrações de CO, H2 e CH4 foram comparados a resultados experimentais. Um modelo transiente unidimensional também foi analisado. Utilizando a aplicação de um mecanismo de pirólise de dois passos onde o alcatrão primário (ou oxigenados) são inicialmente formados e então craqueados em alcatrão secundário (ou hidrocarbonetos) e outros gases combustíveis. Assim se revela a complexidade dos processos físicos e químicos que ocorrem no reator pelo uso do balanço de energia e massa e com informações das taxas de reação das reções químicas e os processos de transporte físicos. O modelo computacional é capaz de prever o perfil da composição de gases, temperatura, alcatrão primário e secundário ao longo do eixo longitudinal do gaseificador. Foram obtidos resultados para simulações realizadas nos dois modelos e posteriormente analisado tal comportamento em comparação ao resultado experimental obtidos por Santos (2011).