No abstract

No abstract

Application of a high electric field causes an electric shock to the heart. This is utilized in defibrillation to reestablish normal contraction rhythms during dangerous arrhythmias or in cardiac arrest. If shock-induced transmembrane potentials are large enough, they can cause tissue destruction due to irreversible electroporation (EP). Also electrochemotherapy of nearby tissues may have an adverse effect on the heart. Herein, we present experimental data on effects of electroporation in culture of cardiac cells (H9C2). The electric field was applied in short pulses of 25-3250 V/cm, 50 µs each. The viability of cells was tested by MTT assay after 24 hours. For detection of DNA fragmentation, associated with apoptosis, alkaline and neutral comet assays were performed after EP. Additionally phase contrast images of cells obtained directly after EP were analyzed. Although cell images indicated disruption of cell membranes after EP with high intensities, only a few percent of apoptotic cells and no necrotic effects in the cell nucleus could be observed in comet assay tests performed 2 hours post EP. MTT viability test showed that pulse intensities above 375 V/cm are destructive for myocytes viability.

The membrane cofactor protein, CD46 represents a complement inhibitor, which protects autologous cells from complement-mediated cytotoxicity. On tumor cells, CD46 may exhibit the potential to protect them from immune responses of the host. The present study aimed at evaluation of prognostic significance of CD46 expression in breast cancers. The analyses were performed on 70 samples of breast cancer. Immunohistochemical reactions were performed on paraffin sections of studied tumors using monoclonal antibodies directed against CD46. Results of the immunohistochemical reactions and of clinical observations were subjected to statistical analysis. Multivariate analysis showed that expression of CD46 and involvement of lymph nodes represent independent risk factors for disease-free survival and overall survival. Kaplan-Meier analysis showed that patients with tumors negative for CD46 have an increased progression-free time and overall survival time as compared with patients with the CD46-positive tumors. The study demonstrates that breast cancers manifest CD46 expression and that it is linked to a less favorable prognosis.

No abstract