Biomarcadores, índices y algoritmos para el diagnóstico de fibrosis hepática en pacientes con hepatitis crónica por virus C / Biomarkers, indexes and algorithms for the detection of liver fibrosis in chronic hepatitis C patients

Determinar el estadio de fibrosis hepática es esencial en el manejo de la enfermedad hepática en pacientes con hepatitis crónica por virus C. La biopsia hepática ha sido considerada el gold standard para diagnosticar la enfermedad, la actividad necroinflamatoria y el estadio de fibrosis, pero tiene algunas limitaciones técnicas y riesgos. Teniendo en cuenta estas limitaciones, existe cierta exigencia en introducir biomarcadores séricos no invasivos para el diagnóstico de fibrosis que podrían ser capaces de reemplazar parcialmente a la biopsia hepática. El biomarcador sérico ideal debería ser específico para el hígado y fácil de determinar. Los marcadores séricos se dividen en directos e indirectos. Los directos reflejan el recambio de la matriz extracelular, mientras que los indirectos reflejan alteraciones en la función hepática. Aunque todavía está limitado el grado de implementación de los test no invasivos de fibrosis hepática, esta revisión es una visión de conjunto de los biomarcadores, índices y algoritmos diagnósticos de fibrosis hepática estudiados en hepatitis crónica C pero con un interés potencial en otras hepatopatías crónicas (AU)

Precise staging of liver fibrosis is essential in the management of liver disease activity in chronic hepatitis C patients. Liver biopsy has been considered the reference method for diagnosing disease, grading necroinflammatory activity, and staging fibrosis, but it has some technical limitations and risks. Taking into account these limitations, there is a need to introduce non-invasive serum markers for fibrosis that would be able to partially replace liver biopsy. Ideal serum markers should be specific for the liver and easy to perform. Serum markers of hepatic fibrosis are divided into direct and indirect. Direct markers reflect extracellular matrix turnover, whereas indirect markers reflect alterations in hepatic function. The degree of implementation of non-invasive diagnostic tests for liver fibrosis still remains limited. This review provides a current overview of biomarkers, indexes and algorithms for hepatic fibrosis diagnosis in chronic hepatitis C patients (AU)

Two-color nanoscopy of three-dimensional volumes by 4Pi detection of stochastically switched fluorophores.

We demonstrate three-dimensional (3D) super-resolution imaging of stochastically switched fluorophores distributed across whole cells. By evaluating the higher moments of the diffraction spot provided by a 4Pi detection scheme, single markers can be simultaneously localized with <10 nm precision in three dimensions in a layer of 650 nm thickness at an arbitrarily selected depth in the sample. By splitting the fluorescence light into orthogonal polarization states, our 4Pi setup also facilitates the 3D nanoscopy of multiple fluorophores. Offering a combination of multicolor recording, nanoscale resolution and extended axial depth, our method substantially advances the noninvasive 3D imaging of cells and of other transparent materials.

Change of platelet activation markers using flow cytometry in patients with hematology/oncology disorders after transfusion.

In spite of the frequent need of platelet transfusions, there is limited information on the association of platelet activation markers, in transfused patients with hematology/oncology disorders, with platelet function using flow cytometry. The goal of this study was to evaluate the changes of PAC-1 binding and CD62P expression, with or without agonists in patients after transfusions. Twenty-eight whole blood samples were obtained from 24 patients admitted to the department of Hematology & Oncology and transfused with platelets; these samples were compared to 30 healthy controls. Whole blood samples, either with or without agonists, such as 20 microM adenosine diphosphate (ADP) or 100 microM thrombin receptor activating peptide (TRAP), were stained with the fluorescein conjugated monoclonal antibodies PAC-1 or CD62P. Then, the percent expression for each marker was analysed using flow cytometry. ADP and TRAP induced an increased percentage of CD62P expression and PAC-1 binding after platelet transfusions compared to the samples studied before transfusion, and these findings were lower than those of the healthy controls. However, the expression of platelets without the agonists was not significantly changed, despite the transfusions. Therefore, agonist-induced platelet activation markers, studied by flow cytometry, appear to be more useful for the evaluation of platelet function after transfusions than platelet activation markers without agonists.

Activated platelets in transient global amnesia and TIA.

To assess whether platelets are activated in transient global amnesia (TGA) and TIA, blood samples were analyzed by fluorescence-activated cytoscan using antibodies specific for platelet fibrinogen receptor (PAC1) and P-selectin (CD62P). Samples from TIA contained high levels of CD62P compared with age-matched control subjects, whereas those from TGA did not. The authors suggest that activated platelets are involved in brain ischemia, whereas ischemia appears not to be associated with most TGA.