Anticorpos antifosfolípides em 66 pacientes com infarto cerebral entre 15 e 40 anos Antiphospholipid antibodies in 66 patients with cerebral infarction between 15 and 40 years old

Os anticorpos antifosfolípides (aFLs) constituem grupo heterogêneo de imunoglobulinas que tem sido relacionado com alterações na coagulabilidade. Indivíduos com títulos elevados teriam maior probabilidade de desenvolver tromboses de repetição, tanto arterial como venosa, e por conseguinte infarto cerebral (IC). Os testes para detecção mais utilizados em estudos clínicos são o inibidor lúpico e a anticardiolipina. Têm-se relatado maiores percentuais de positividade nesses testes em pacientes jovens com IC. Neste estudo procuramos investigar a prevalência desses anticorpos em pacientes com IC entre 15 e 40 anos em nosso Serviço. Examinamos 66 pacientes para presença de aFLs e obtivemos 16,65% de resultados positivos. Confirmamos diagnóstico de síndrome do anticorpo antifosfolípide primária em três (4,55%) casos. Concluímos que a pesquisa de rotina para aFLs em pacientes jovens com IC está indicada neste grupo de pacientes, mas correlacioná-los com o episódio isquêmico nem sempre é possível.<br>The antiphospholipid antibodies (aPLs) are a heterogenous group of immunoglobulins that have been related with alterations in blood coagulability in recent years. Patients with elevated titers of these antibodies have a high probability to develop thrombotic events, including cerebral infarct (CI). The tests currently used to detect these antibodies are the lupus anticoagulant and ELISA for anticardiolipin antibodies which have a larger proportion of positivity among young patients with CI. In our study we tested 66 patients with cerebral infarcts whose ages ranged from 15 to 40 years for the presence of lupus anticoagulant and anticardiolipin antibodies. The results showed that eleven (16.65%) patients were positive for aPLs and three (4.55%) of them fulfilled the diagnostic criteria for primary antiphospholipid syndrome. These data point out to the importance of investigating aPLs in young patients with CI and its high prevalence in this group compared with healthy population

Biodegradation of acetonitrile by adapted biofilm in a membrane-aerated biofilm reactor

10.1007/s10532-008-9246-7Biodegradation204569-580BIOD

Catalytic activation of β-arrestin by GPCRs

β-arrestins are critical regulator and transducer proteins for G-protein-coupled receptors (GPCRs). β-arrestin is widely believed to be activated by forming a stable and stoichiometric GPCR-β-arrestin scaffold complex, which requires and is driven by the phosphorylated tail of the GPCR. Here we demonstrate a distinct and additional mechanism of β-arrestin activation that does not require stable GPCR-β-arrestin scaffolding or the GPCR tail. Instead, it occurs through transient engagement of the GPCR core, which destabilizes a conserved inter-domain charge network in β-arrestin. This promotes capture of β-arrestin at the plasma membrane and its accumulation in clathrin-coated endocytic structures (CCSs) after dissociation from the GPCR, requiring a series of interactions with membrane phosphoinositides and CCS-lattice proteins. β-arrestin clustering in CCSs in the absence of the upstream activating GPCR is associated with a β-arrestin-dependent component of the cellular ERK (extracellular signal-regulated kinase) response. These results delineate a discrete mechanism of cellular β-arrestin function that is activated catalytically by GPCRs