6 research outputs found

    Anti-erythroblast autoimmunity in early myelodysplastic syndromes.

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    Background and Objectives Autoimmune phenomena, mainly directed against red blood cells are described in myelodysplastic syndromes (MDS), particularly early MDS, i.e. refractory anemia (RA) and RA with ringed sideroblasts (RARS). Dysregulation of apoptosis and immunoregulatory cytokines are thought to play a role in the pathogenesis of MDS.Design and Methods This work was aimed to investigate anti-erythroid autoimmunity in unstimulated and mitogen-stimulated peripheral blood and bone marrow cultures of 26 patients with early MDS (RA and RARS), and to relate its presence with apoptotic markers and cytokine production. Bone marrow cytokine production in culture supernatants, and caspase-3 and nuclear factor-κB activity in cell extracts were tested by enzyme-linked immunosorbent assays.Results Fourteen of the 26 (53.8%) patients showed the presence of autoantibodies in bone marrow cultures, whereas none displayed a positive direct antiglobulin test in peripheral blood cultures. Incubation of culture supernatants from positive patients with autologous CD45– enriched-cell suspensions showed that the autoimmune reaction was directed against autologous erythroblasts. These patients had mild signs of hemolysis and increased numbers of erythroblasts, compared with negative patients. Patients with anti-erythroblast autoimmunity displayed higher caspase-3 activity and lower tumor necrosis factor-αand interleukin-4 production than did negative patients.Interpretation and Conclusions Half of the patients with early MDS showed autoimmunity against erythroblasts. This evidence might support a more rationale use of steroid therapy in these patients. The lower levels of cytokines in patients with anti-erythroblast autoimmunity are consistent with the suggested hypothesis that the autoimmune phenomena observed in MDS are probably initiated and perpetuated through alterations of pro-inflammatory and/or immunoregulatory cytokine production

    Ação de diferentes preparações de extrato pirolenhoso sobre Brevipalpus phoenicis (GEIJSKES) Action of different pyroligneous extract preparations when applied on Brevipalpus phoenicis (GEIJSKES)

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    O objetivo deste trabalho foi avaliar a forma de ação de duas preparações de extrato pirolenhoso aplicadas diretamente sobre Brevipalpus phoenicis, que é o ácaro vetor da leprose dos citros, um dos principais problemas da citricultura Paulista. Para o experimento, foram utilizados ácaros adultos mantidos numa criação-estoque no laboratório de Acarologia da UNESP - Universidade Estadual Paulista, em Jaboticabal-SP. Os tratamentos foram constituídos por duas diferentes preparações (destilado e decantado) de extrato pirolenhoso de eucalipto nas proporções EP:água de 1:600; 1:300 (normalmente recomendadas); 1:150; 1:75; 1:38; 1:19 e de água (testemunha), com 7 repetições. Cada parcela foi constituída de 10 ácaros mantidos sobre um fruto de laranja, em arena de 2,5 cm de diâmetro, delimitada com cola adesiva tipo Tanglefoot®. As aplicações foram efetuadas em Torre de Potter, pulverizando-se 2 mL por fruto das soluções correspondentes aos diferentes tratamentos. Os frutos foram mantidos em sala climatizada a 27&plusmn;1ºC, e as avaliações foram realizadas 24 e 48 horas após a aplicação dos tratamentos, determinando-se o número de ácaros mortos (mortalidade) e retidos na barreira adesiva (repelência). Os dois tipos de extrato pirolenhoso testados não apresentaram repelência significativa sobre Brevipalpus phoenicis; ambos induziram mortalidade significativa somente para concentrações acima de 1:150, com efeito mais pronunciado para o destilado; há um aumento na mortalidade de 24 para 48 horas após a aplicação; a ação protetora preconizada pela aplicação de baixas doses (1:300 a 1:600) nas plantas não é devida à mortalidade e repelência pelo contato direto do extrato pirolenhoso sobre os ácaros.<br>The aim of this work was to evaluate the acaricide and repellent effects of two different pyroligneous extract preparations (PE) applied directly on Brevipalpus phoenicis. This mite is the vector or citrus leprosies, which is one of the main problems of São Paulo State citrus culture. This experiment was carried out with mites derived of the colony-supply maintained in the laboratory of Acarology of the Unesp - São Paulo State University, at Jaboticabal. The experiment consisted of application of water (control) and two distinct way of preparations (distilled and decanted) of pyroligneous extract (PE) of eucalyptus in 6 volumetric ratios PE: water of 1:600, 1:300, 1:150, 1:75, 1:38 and 1:19, with 7 replications. Each plot with 10 mites maintained on an orange fruit, in enclosure of 2.5 cm diameter isolated by Tanglefoot® (The Tanglefoot Company: USA) adhesive barrier. After confection of the enclosures and mites transference, 2 mL of the solutions corresponding to the different treatments were applied per fruit, by using a Potter&acute;s Tower. Then, the fruits were maintained in a room at 27&plusmn;1ºC, and evaluations of the number of dead mites (mortality) and restrained in the adhesive barrier (repellence) were carried out 24 and 48 hours after treatment application. The distilled PE presented more mortality in comparison to decanted PE for concentrations higher than 1:150. None of two types of extract showed significant repellence effect on B. phoenicis. The protective action recognized for low doses (1:300 to 1:600, normally recommended), is not due to mortality or repellence by direct contact of these products with mites
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