ABSTRACT
Activation of protein-activated receptor (PAR-1) by thrombin potentiates the hyposmotic efflux of (3)H-D-aspartate and (3)H-taurine from cultured cerebellar astrocytes. This effect is mediated by a thrombin-elicited increase in cytosolic Ca(2+) levels [Ca(2+)](i) and the activation of phosphoinositide-3-kinase (PI3K). These signalling pathways operate independently showing additive effects if prevented simultaneously. The contribution of the Ca(2+)-mediated pathway to thrombin-increased D-aspartate or taurine efflux, evaluated by the inhibitory effect of preventing [Ca(2+)](i) rise, was higher for D-aspartate (64% efflux decrease) than for taurine (40% decrease). The PI3K blocker decreased 48% and 36% D-aspartate and taurine efflux, respectively. Hyposmolarity increases phosphorylation of EGFR and c-src, but thrombin did not enhance this effect. Blockade of EGFR/src phosphorylation marginally reduced (11-14%) the hyposmolarity plus thrombin efflux of D-aspartate; taurine efflux was more sensitive to these blockers (18-26%). Since thrombin has no effect increasing EGFR/src phosphorylation in astrocytes, the contribution of this transactivation pathway may represent the inhibition of the hyposmotic efflux solely.
Subject(s)
Astrocytes/metabolism , Glutamic Acid/metabolism , Signal Transduction/physiology , Taurine/metabolism , Thrombin/metabolism , Animals , Astrocytes/cytology , Calcium/metabolism , Cells, Cultured , ErbB Receptors/metabolism , Humans , Osmolar Concentration , Phosphatidylinositol 3-Kinases/metabolism , Phosphoinositide-3 Kinase Inhibitors , src-Family Kinases/metabolismABSTRACT
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Subject(s)
Adult , Male , Humans , Hip , Rectal Fistula/complications , Rectal Fistula/diagnosis , Abscess/complications , Abscess/diagnosis , Crohn Disease/complications , Pain/etiology , Tomography, X-Ray Computed , Magnetic Resonance SpectroscopyABSTRACT
BACKGROUND: The antiphospholipid antibody syndrome (AAS), which is characterized by thromboembolic events and/or fetal loss and/or low platelet count associated with antiphospholipid antibodies, may evolve with acute myocardial infarction (AMI). The presence of AAS among young patients with AMI ranges from 14% to 21%, and this condition implies specific therapeutic attitudes as new thrombotic events may occur, according to some authors. MATERIALS AND METHODS: A prospective study was undertaken with 25 patients aged > or = 65 years with AMI that were admitted to our institution during one year who were compared with control patients with similar risk factors. IgG and IgM anticardiolipin antibodies (ACA) were measured in the first 24 hours since the onset of AMI symptoms and three months later. RESULTS: The follow-up ranged from three months to one year. Among patients, ACA positivity in the two measurements was higher (12%) than that observed in the control group (5%) (p = 0.36). ACA positivity on two occasions was not a risk factor for new thrombotic events. CONCLUSION: ACA positivity is higher among AMI patients (measured early and at three months) than among the general population although the presence of such antibodies does not increase the risk for new post-infarction thrombotic events.
Subject(s)
Antiphospholipid Syndrome/complications , Antiphospholipid Syndrome/epidemiology , Myocardial Infarction/etiology , Adult , Age Factors , Aged , Female , Humans , Male , Middle Aged , Prevalence , Prospective StudiesABSTRACT
Introducción. El síndrome antifosfolípido (SAFL), caracterizado por fenómenos trombóticos y/o pérdidas fetales y/o plaquetopenia asociados a anticuerpos antifosfolípidos, puede cursar con infarto agudo de miocardio (IAM). La presencia de SAFL en pacientes jóvenes con IAM oscila entre el 14 por ciento y el 21 por ciento, patología que conlleva actitudes terapéuticas específicas al presentar en su evolución nuevos eventos trombóticos según algunos autores. Material y métodos. Se realiza un estudio prospectivo en 25 pacientes con IAM y edad inferior o igual a 65 años que ingresaron en nuestro centro a lo largo de un año, comparándolos con controles con factores de riesgo similares. Se determinan anticuerpos anticardiolipina (ACA) IgG e IgM en las primeras 24 horas desde el inicio de la clínica de IAM y a los tres meses. Resultados. El seguimiento osciló entre tres meses y un año. En el grupo de pacientes, la positividad de ACA en las dos determinaciones fue superior (12 por ciento) a la del grupo control (5 por ciento) (p = 0,36). La positividad de ACA en dos ocasiones no fue un factor de riesgo para nuevos eventos trombóticos. Conclusión. La positividad de ACA es superior en el grupo de pacientes con IAM (determinados precozmente y a los tres meses) que en la población general, si bien la presencia de dichos anticuerpos no incrementa el riesgo de nuevos eventos trombóticos postinfarto (AU)
