Imbalance in Coagulation/Fibrinolysis Inhibitors Resulting in Extravascular Thrombin Generation in Gliomas of Varying Levels of Malignancy.

Neoplastic processes are integrally related to disturbances in the mechanisms regulating hemostatic processes. Brain tumors, including gliomas, are neoplasms associated with a significantly increased risk of thromboembolic complications, affecting 20-30% of patients. As gliomas proliferate, they cause damage to the brain tissue and vascular structures, which leads to the release of procoagulant factors into the systemic circulation, and hence systemic activation of the blood coagulation system. Hypercoagulability in cancer patients may be, at least in part, a result of the inadequate activity of coagulation inhibitors. The aim of the study was to evaluate the expression of the inhibitors of the coagulation and fibrinolysis systems (tissue factor pathway inhibitor, TFPI; tissue factor pathway inhibitor-2 TFPI-2; protein C, PC; protein S, PS, thrombomodulin, TM; plasminogen activators inhibitor, PAI-1) in gliomas of varying degrees of malignancy. Immunohistochemical studies were performed on 40 gliomas, namely on 13 lower-grade (G2) gliomas (8 astrocytomas, 5 oligodendrogliomas) and 27 high-grade gliomas (G3-12 anaplastic astrocytomas, 4 anaplastic oligodendrogliomas; G4-11 glioblastomas). A strong expression of TFPI-2, PS, TM, PAI-1 was observed in lower-grade gliomas, while an intensive color immunohistochemical (IHC) reaction for the presence of TFPI antigens was detected in higher-grade gliomas. The presence of PC antigens was found in all gliomas. Prothrombin fragment 1+2 was observed in lower- and higher-grade gliomas reflecting local activation of blood coagulation. Differences in the expression of coagulation/fibrinolysis inhibitors in the tissues of gliomas with varying degrees of malignancy may be indicative of their altered role in gliomas, going beyond that of their functions in the hemostatic system

Heterogeneous Expression of Proangiogenic and Coagulation Proteins in Gliomas of Different Histopathological Grade.

Brain gliomas are characterized by remarkably intense invasive growth and the ability to create new blood vessels. Angiogenesis is a key process in the progression of these tumors. Coagulation and fibrinolysis factors play a role in promoting angiogenesis. The aim of the study was to evaluate the expression of proangiogenic proteins (VEGF and bFGF) and hemostatic proteins (TF, fibrinogen, fibrin, D-dimers) associated with neoplastic cells and vascular endothelial cells in brain gliomas of various degrees of malignancy. Immunohistochemical tests were performed using the ABC method with the use of mono- and polyclonal antibodies. The obtained results indicated that both neoplastic cells and vascular endothelial cells in gliomas of various degrees of malignancy are characterized by heterogeneous expression of proteins of the hemostatic system and angiogenesis markers. The strongest expression of proangiogenic factors and procoagulant factors was demonstrated in gliomas of higher-grade malignancy

Hemodialysis Removes Uremic Toxins That Alter the Biological Actions of Endothelial Cells

Chronic kidney disease is linked to systemic inflammation and to an increased risk of ischemic heart disease and atherosclerosis. Endothelial dysfunction associates with hypertension and vascular disease in the presence of chronic kidney disease but the mechanisms that regulate the activation of the endothelium at the early stages of the disease, before systemic inflammation is established remain obscure. In the present study we investigated the effect of serum derived from patients with chronic kidney disease either before or after hemodialysis on the activation of human endothelial cells in vitro, as an attempt to define the overall effect of uremic toxins at the early stages of endothelial dysfunction. Our results argue that uremic toxins alter the biological actions of endothelial cells and the remodelling of the extracellular matrix before signs of systemic inflammatory responses are observed. This study further elucidates the early events of endothelial dysfunction during toxic uremia conditions allowing more complete understanding of the molecular events as well as their sequence during progressive renal failure

Micromechanical Properties of Injection-Molded Starch–Wood Particle Composites

The micromechanical properties of injection molded starch–wood particle composites were investigated as a function of particle content and humidity conditions. The composite materials were characterized by scanning electron microscopy and X-ray diffraction methods. The microhardness of the composites was shown to increase notably with the concentration of the wood particles. In addition,creep behavior under the indenter and temperature dependence were evaluated in terms of the independent contribution of the starch matrix and the wood microparticles to the hardness value. The influence of drying time on the density and weight uptake of the injection-molded composites was highlighted. The results revealed the role of the mechanism of water evaporation, showing that the dependence of water uptake and temperature was greater for the starch–wood composites than for the pure starch sample. Experiments performed during the drying process at 70°C indicated that the wood in the starch composites did not prevent water loss from the samples.Peer reviewe