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1772. Numerical modeling in electroporation-based biomedical applicationsNataša Pavšelj, Damijan Miklavčič, 2008, original scientific article Abstract: Background. Numerous experiments have to be performed before a biomedical application is put to practical use in clinical environment. As a complementary work to in vitro, in vivo and medical experiments, we can use analytical and numerical models to represent, as realistically as possible, real biological phenomena of, in our case, electroporation. In this way we canevaluate different electrical parameters in advance, such as pulse amplitude, duration, number of pulses, or different electrode geometries. Suchnumerical models can contribute significantly to the understanding of an experiment and treatment planning as well as to the design of new electroporation devices and electrodes. Methods. We used commercially available modeling software, based on finite element method. We constructed a model of a subcutaneous tumor during electrochemotherapy (EMAS) and a model ofskin during gene electrotransfer (COMSOL Multiphysics). Tissue-electrode geometries, pulse parameters and currentvoltage measurements from in vivo experiments were used to develop and validate the models. Results. To describeadequately our in vivo observations, a tissue conductivity increase during electroporation was included in our numerical models. The output currents of the models were compared to the currents and the voltages measuredduring in vivo experiments and a good agreement was obtained. Also, when comparing the voltages needed for a successful electropermeabilization assuggested by the models, to voltages applied in experiments and achieving a successful electrochemotherapy or in vivo gene electrotransfer, good agreementcan be observed. Conclusions. Modeling of electric current and electric field distribution during cell and tissue electroporation proves to be helpful in describing different aspects of the process and allowing us to design electrodes and electroporation protocols as a part of treatment planning. Keywords: electroporation, gene electrotransfer, electrochemotherapy, subcutaneous tumor, finite-element method Published in DiRROS: 07.03.2024; Views: 434; Downloads: 107
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1773. Ecotoxicologically relevant cyclic peptides from cyanobacterial bloom (Planktothrix rubecens) - a threat to human and environmental healthBojan Sedmak, Tina Eleršek, Olga Grach-Pogrebinsky, Shmuel Carmeli, Nataša Sever, Tamara Lah Turnšek, 2008, original scientific article Abstract: Background. The information of the overall production of major cyanobacterial cyclic peptides in a water body is essential for risk assessment and for the prediction of future development of the bloom. A procedure that gives a reviewof both toxic and non-hepatotoxic hydrophilic cyclic peptide production is important to evaluate the ecological conditions in the water environment and to predict the release of dangerous toxic and tumour promoting substances.Methods. The cyclic peptides were identified on the basis of their retention times, characteristic spectra, molecular masses and biological activity. The non-hepatotoxic cyclic peptides were characterised by their inhibition of porcine pancreatic elastase, while cytotoxicity to mammalian cells was tested with the MTT test on B16 cell line. Conclusions. The method presented gives a rapid, simultaneous assessment, preliminary identification and estimation of bioactive cyclic peptides. The synthesis of non-hepatotoxic cyclic peptides can mediate the release various toxic and otherwise biologically active substances that induce systemic genotoxicity in mammals. Keywords: tumor promoters, microcystin, anabaenopeptin, planktopeptin, toxic cyanobacterial blooms, environmental health Published in DiRROS: 07.03.2024; Views: 376; Downloads: 96
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1776. DNA quadruplex structure with a unique cation dependencyMartin Gajarský, Petr Stadlbauer, Jiří Šponer, Anne Cucchiarini, Michaela Dobrovolna, Vaclav Brazda, Jean-Louis Mergny, Lukáš Trantírek, Martina Lenarčič Živković, 2024, original scientific article Published in DiRROS: 07.03.2024; Views: 501; Downloads: 335
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1779. Targeted gene therapy in radiotherapyUrška Kamenšek, Gregor Serša, 2008, review article Abstract: The dramatic pace in development of gene therapy over the past decades has made it a realistic alternative for the treatment of cancer. Radiotherapy, on the other hand, is one of the most commonly used and well established cancer treatment modalities. The latest improvements in the physical targeting ability of radiotherapy and understanding of the molecular mechanism involved in the cellular response to ionizing radiation have presented an opportunity to combine radiotherapy with gene therapy. This review article will focus on gene therapy strategies that can be used to enhance the effectiveness of radiotherapy, with an emphasis on transcriptional targeting approaches. Published in DiRROS: 07.03.2024; Views: 328; Downloads: 83
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