Danijela Cvetkovic

Antiproliferative and proapoptotic activities of methanolic extracts from Ligustrum vulgare L. as an individual treatment and in combination with palladium complex.

The aim of this study is to examine the growth inhibitory effects of methanolic leaf and fruit extracts of L. vulgare on HCT-116 cells over different time periods and their synergistic effect with a Pd(apox) complex. The antiproliferative activity of plant extracts alone or in combination with the Pd(apox) complex was determined using MTT cell viability assay, where the IC50 value was used as a parameter of cytotoxicity. Results show that antiproliferative effects of L. vulgare extracts increase with extension of exposure time, with decreasing IC50 values, except for 72 h where the IC50 values for methanolic leaf extract were lower than for the fruit extract. The Pd(apox) complex alone had a weak antiproliferative effect, but combination with L. vulgare extracts caused stronger effects with lower IC50 values than with L. vulgare extracts alone. The type of cell death was explored by fluorescence microscopy using the acridin orange/ethidium bromide method. Treatments with plant extracts caused typical apoptotic morphological changes in HCT-116 cells and co-treatments with Pd(apox) complex caused higher levels of apoptotic cells than treatment with plant extracts alone. The results indicate that L. vulgare is a considerable source of natural bioactive substances with antiproliferative activity on HCT-116 cells and which have a substantial synergistic effect with the Pd(apox) complex.

Electromagnetic field investigation on different cancer cell lines

BackgroundThere is a strong interest in the investigation of extremely low frequency Electromagnetic Fields (EMF) in the clinic. While evidence about anticancer effects exists, the mechanism explaining this effect is still unknown.MethodsWe investigated in vitro, and with computer simulation, the influence of a 50 Hz EMF on three cancer cell lines: breast cancer MDA-MB-231, and colon cancer SW-480 and HCT-116. After 24 h preincubation, cells were exposed to 50 Hz extremely low frequency (ELF) radiofrequency EMF using in vitro exposure systems for 24 and 72 h. A computer reaction-diffusion model with the net rate of cell proliferation and effect of EMF in time was developed. The fitting procedure for estimation of the computer model parameters was implemented.ResultsExperimental results clearly showed disintegration of cells treated with a 50 Hz EMF, compared to untreated control cells. A large percentage of treated cells resulted in increased early apoptosis after 24 h and 72 h, compared to the controls. Computer model have shown good comparison with experimental data.ConclusionUsing EMF at specific frequencies may represent a new approach in controlling the growth of cancer cells, while computer modelling could be used to predict such effects and make optimisation for complex experimental design. Further studies are required before testing this approach in humans.

Real-time monitoring of cytotoxic effects of electroporation on breast and colon cancer cell lines.

PURPOSE To study the effects of electroporation on different cell lines. MATERIAL The effects of electroporation on human breast cancer (MDA-MB-231), human colon cancer (SW-480 and HCT-116), human fibroblast cell line (MRC-5), primary human aortic smooth muscle cells (hAoSMC) and human umbilical vein endothelial cells (HUVEC) were studied. Real-time technology was used for cell viability monitoring. Acridine orange/ethidium bromide assay was applied for cell death type determination. A numerical model of electroporation has been proposed. RESULTS Electroporation induced inhibition of cell viability on dose (voltage) dependent way. The electroporation treatment 375-437.5Vcm-1 caused irreversible electroporation of cancer cells and reversible electroporation of healthy cells. The application of lower voltage rating (250Vcm-1) led to apoptosis as the predominant type of cell death, whereas the use of higher voltage (500Vcm-1) mainly caused necrosis. CONCLUSION Electroporation represents a promising method in cancer treatment. Different cancer cell lines had different response to the identical electroporation treatment. Electroporation 375-437.5Vcm-1 selectively caused permanent damage of cancer cells (SW-480), while healthy cells (MRC-5, hAoSM and HUVEC) recovered after 72h. The type of cell death is dependent of electroporation conditions. The proposed numerical model is useful for the analysis of phenomena related to electroporation treatment.

Experimental and numerical investigation of electromagnetic field at different cancer cell lines

There is a strong interest of investigation of Extremely Low Frequency (ELF) ElectroMagnetic (EM) fields in the clinic. In this study we investigated experimentally in-vitro and in-sillico with computer simulation influence of 50 Hz EM field at three different cancer cell lines: breast cancer MDA-MB-231 and colon cancer SW-480 and HCT-116. Computer reaction-diffusion model with the net rate of cell proliferation and effect of electromagnetic field in time was developed. The fitting procedure for estimation of the computer model parameters was implemented. Experimental and computer model data have shown good comparison. These findings can open a new avenue for better controlling the growth of cancer cells at specific frequencies without affecting normal tissues, which may have a great influence in clinical oncology.

Optimization of Parameters for Electrochemical Detection: Computer Simulation and Experimental Study

It has been shown that for each electrochemical measurement it is necessary first to optimize all the parameters that influence the obtained electrochemical signal. This is a time-consuming process and that is why in this study we focused on the computer simulation of the influence of multiparameters on the electrochemical signal. Herein we used a model system of the electroreduction of ruthenium(III) salt on gold electrode in phosphate buffer solution. Ru3+ is often used as redox probe for detection and understanding of nucleic acid hybridization on the electrodes. This study should reveal some new aspects of using the computer simulations in determining the optimal measuring conditions for detection of RNA/PNA hybridoms on the gold surface.

Length of Hospital Stay and Bed Occupancy Rates in Former Yugoslav Republics 1989–2015

Recent decades have been witnesses that developing world economies preceded global economic growth with all the consequences on healthcare systems of their countries. Complex and dynamic socioeconomic and technological evolution, primarily in free market of capitalist economies as well as in former socialist countries/economies with some postponement, provided significant advances and improvements in health outcomes (Jakovljevic and Ogura, 2016). Large differences in the quality of health systems are evident. Globalization among many changes led to the creation of so called emerging markets. The one with the most intensive development were marked by Goldman Sachs as BRICS European region offers great opportunities for studying variations in the magnitude of inequalities in health system quality because of the numerous intercountry varieties of political, cultural, economic, and epidemiologic nature (Arcaya et al., 2015). Eastern Europe and Balkans allow very good insight whether states with history of recent period of war, political instability, economic crisis, and different types of health care reforms have larger inequalities in health than countries elsewhere in Europe and worldwide (Mackenbach et al., 2008). We conducted a study within former Yugoslav republics, today independent countries and tried to identify some of the indicators determining these variations. A shortage of published data related to the consequences of SouthEastern European transition on healthcare is evident, especially regarding former Yugoslavia. The civil war events between 1989 and 1995 initiated a huge wave of socioeconomic changes in the whole region of the Balkans that inevitably influenced national health systems quality referring to health care provision, planning and financing. These reforms were significantly more prosperous in some states of former Yugoslavia compared to the others (Jakovljevic et al., 2015a). National health system of former Yugoslavia was actually something in between Western European and Eastern Soviet bloc financing pattern. Serbia is the largest Western Balkans medical equipment and pharmaceutical market in terms of population size as well as the value of sales among neighboring non-EU countries. Global recession caused serious problems in provision of sustainable financing and increased shortages of pharmaceuticals and medical equipment across the region of former Yugoslavia (Jakovljevic et al., 2015b). Health insurance systems are similar in all former Yugoslav republics. All employed citizens are insured and they use health care services in public health care institutions as well as in private institutions which have a signed contract with the Health Insurance Fund, a legal entity established by the Republic Ministry of Health. …

Numerical modeling of behavior of cancer cells after electroporation

One of the approaches that could be used for cancer treatment is electroporation. This is a relatively new technique and thus its effect on various cancer cell types should be analyzed in detail. In this paper numerical simulations are used, in order to model the behavior of cells after electroporation. Fitting procedure was used for estimation of the parameters of the computer model. This model enables continuous tracking of changes in cell viability and provides some quantitative information about the effect of electric field (change in proliferation and death rate, oxygen consumption etc.). The accuracy of the model is validated using experimental data.