RESUMO
The underlying cause behind the accelerated destruction of erythrocytes in the bone marrow and in the peripheral circulation, accompanying the beta-thalassemic syndromes is still not clearly understood. The present investigation demonstrates that increased phagocytosis of erythrocytes in E beta-thalassemia is inhibited by the presence of phosphatidylserine (PS) vesicles, suggesting a PS-'PS-receptor' type of interaction in premature recognition of these erythrocytes by macrophages. Increased exposure of both aminophospholipids phosphatidylethanolamine (PE) and PS was demonstrated by fluorescamine labeling and annexin binding, respectively. The slower rate of translocation of PS across the bilayer suggested that this contributed towards the increased exposure of PS in E beta-thalassemic erythrocytes.
Assuntos
Membrana Eritrocítica/química , Hemoglobina E , Fosfatidilserinas/sangue , Talassemia beta/sangue , Anexinas/sangue , Membrana Eritrocítica/ultraestrutura , Humanos , Bicamadas Lipídicas , Macrófagos/fisiologia , Fagocitose , Fosfatidiletanolaminas/sangue , Propriedades de SuperfícieRESUMO
The 'Modified Sturm Test' uses carbon dioxide production as the primary end point in assessing the biodegradation potential of organic chemicals. This test was conducted by a commercial laboratory to assess the potential biodegradability of an oil stabilizer sample from an oil company in Canada. There was a high percentage conversion of total organic carbon present in the sample but carbon dioxide measured was low. Many possibilities were analyzed in this paper in order to understand the situation. The analysis showed that the test was subject to criticism from the point of view of CO2 measurement, 10-day window period, and aeration/mixing conditions.