Logo

Publikacije (237)

Nazad
Mirjana Popsavin, Saša Spaić, Miloš Svirčev, V. Kojić, G. Bogdanovic, V. Popsavin

The known thiazofurin stereoisomer (VII) and two new thiazofurin analogues (XI) and (XII) are synthesized and evaluated for their in vitro antitumor activity.

I. Djan, G. Bogdanovic, S. Šolajić, B. Petrovic, Višnja V. Bogdanović, M. Djan, M. Erak

Biljana Đ. Glišić, Z. Stanić, S. Rajković, V. Kojić, G. Bogdanovic, Miloš I. Đuran

Proton NMR spectroscopy and cyclic voltammetry have been applied to study the stability of three gold(III) complexes with L-histidine-containing peptides, [Au(Gly-L-His-N,N’,N’’)Cl]NO3.1.25H2O (Au1), [Au(L-Ala-L-His-N,N’,N’’)Cl]NO3.2.5H2O (Au2) and [Au(Gly-Gly-L-His-N,N’,N’’,N’’’)]Cl.H2O (Au3) under physiologically relevant conditions. It was found that tridentate coordination of Gly-L-His and L-Ala-L-His dipeptides, as well as tetradentate coordination of Gly-Gly-L-His tripeptide in Au1, Au2 and Au3 complexes, respectively, stabilized +3 oxidation state of gold and prevented its reduction to Au(I) and Au(0). No release of the coordinated peptides from Au(III) was observed under these experimental conditions. Considering remarkable stability of Au1, Au2 and Au3 complexes, their cytotoxic activity was evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay toward five human tumor cell lines, MCF-7 (human breast adenocarcinoma), HT-29 (human colon adenocarcinoma), HeLa (human cervix carcinoma), HL-60 (human promyelocytic leukemia), Raji (human Burkitt’s lymphoma) and one human normal cell line MRC-5 (human fetal lung fibroblasts). While the cytotoxic activity of Au1, Au2 and Au3 against investigated human malignant cell lines was strongly cell line dependent, none of these complexes was cytotoxic against normal MRC-5 cell line. This study can contribute to the future development of gold(III)-peptide complexes as potential antitumor agents.

Ljiljana Suvajdžić, V. Leovac, M. Joksović, G. Bogdanovic, V. Kojić, Nemanja Vujić, Tatjana Mrdja, B. Kocić

Background: Multi-resistant strains multiply daily, populate farms, hospitals and other ecological niches around the world, and cause serious infections in animals and humans, often leading to a fatal outcome. Researchers of all profi les are investigating intensively to finew substances with antimicrobial activity. In the period between 1981 and 2002, 163 new chemical compounds were approved for use as drugs. Synthesized compounds have become much more interesting than the natural ones in the production of new antimicrobial agents. Some of these synthesized compounds are Copper (II) complex. The antimicrobial properties of copper were known in ancient Egypt (2000 BC), where it was used to sterilize water and wounds. Copper is still interesting for today’s research. Materials, Methods & Results: Antimicrobial activity was tested using a microdilution method according to Clinical and Laboratory Standards Institute. The percentage of surviving bacteria was calculated in comparison to the number of bacteria placed in each well. Based on these results, using the Excel software package from Microsoft Offi ce 2007, graphs were generated that showed the percentage of surviving bacteria depending on the corresponding effective concentrations of the tested substance. The function, which was used to approximate the experimental results, was determined using the Power Trendline supplement from the Microsoft Excel program. Cytotoxicity (growth inhibition) was evaluated by tetrazolium colorimetric MTT assay, after exposure of cells to the tested compound for 48 h. Inhibition of growth was expressed as a percentage of cytotoxicity and calculated according to the following equation: (1-A test/A control) x 100. MBC 99.9 and MIC 99 of the test substance were lowest for Arcanobacterium haemolyticum being 0.2 mg/L and 0.0054 mg/L, respectively. The highest values were obtained for Arcanobacterium pyogenes and methicillin-resistant Staphylococcus aureus (MRSA) 488.002 mg/L and 20.2 mg/L. MIC 80 for all four strains ranged from 0.00002 to 0.0023 mg/L. Measured values for MIC 99 are 0.00545 mg/L for A. haemolyticum, 0.0443199 mg/L for R. equi, 0.0520712 mg/L for S. aureus and 2.36378 mg/L for A. pyogenes. Values for MIC 99.9 ranged from 0.236134 to 488,002 mg/L. Most of the MIC values obtained in this study are signifi cantly lower than those reported by other researchers. The values we obtained were lower as compared to MIC values for standard antibiotics, which were considered acceptable by the relevant institutions. This speaks in favor of a stronger antibacterial effect of our tested substances. In regards to cytotoxicity, the obtained MIC 80 doses were lower than toxic, whereas MIC 90 could be classifi ed as low-toxic (less than 0.0625 µM), except of Arcanobacterium pyogenes only. According to the IC50 values, the compound Cu (L) Br2·MeOH was 6.4-fold and 4.8-fold more potent against HCT116 cells compared to normal lung fi broblasts and SW620 cells, respectively. Discussion: Copper (II) complex with an arylpyrazole ligand exhibits strong antibacterial properties, and it shows bacteriostatic effect at concentrations where there is no cytotoxic effect in normal human cells. The emergence of multi-resistant strains of pathogenic bacteria is a growing problem worldwide. Therefore, each new compound with potential antimicrobial activity, especially if it is not cytotoxic in effective dosage, deserves the attention of the scientifi c community. In this paper, we presented a newly synthesized substance with such properties.

UNLABELLED This study aimed at investigating ultrasonographic features of partial hydatidiform mole to establish a proper diagnosis. PATIENTS AND METHODS This was a retrospective study of 70 pregnancies which were divided into two groups: group I--35 pregnant women with a molar pregnancy diagnosed in the first trimester; group II--35 pregnant women with physiological pregnancy spontaneously aborted in the first trimester caused by the cervical insufficiency. Evacuation of the uterus by uterine suction or curettage and pathomorphological analysis ofovular tissue were conducted in both groups. Ultrasonographic parameters were analyzed. RESULTS AND DISCUSSION Theca lutein cysts and hydropic degeneration of villi, enlarged uterus and empty gestational sac, intrauterine hematoma significantly prevailed in the pregnant women with the molar pregnancies. Diagnosis of the partial hydatidiform mole in the first trimester is likely though not enough reliable. Thereby, additional diagnostic methods might be important as well to confirm an early diagnosis of mole.

Nikola Jojić, V. Kojić, D. Kojić, K. Stankov, G. Bogdanovic

Background: Single-walled carbon nanotubes (SWCNTs) have been reported to induce cytotoxicity in different cell lines. Although the mechanisms underlying cytotoxicity are not fully understood, accumulation of reactive oxygen species (ROS) and oxidative damage is considered to be a likely contributing factor. Methods: Human lung carcinoma cells, A549, and human fetal lung fibroblasts, MRC-5 were used to assess the cytotoxicity of SWCNT in the presence and absence of a redox status regulator, N-acetylcysteine (NAC), via the MTT assay. Results: SWCNT induced a nearly three-fold greater loss of viability in A594 vs. MRC-5 cells at ≤250 μg/ml. SWCNT cytotoxicity at higher concentrations was similar for both cell lines, while NAC alone was non-toxic. The cytotoxicity of SWCNT (250 μg/ml) in combination with NAC to A549 cells was significantly decreased at the lowest NAC concentration (1.5 µg/ml), and was similar to NAC treatment alone at that concentration. Higher concentrations of NAC in combination with SWCNT (250 μg/ml) resulted in increased cytotoxicity in both A549 and MRC-5 cells. Conclusion: A549 malignant lung cells are more susceptible to low concentrations of SWCNT vs. normal lung cells, and low concentrations of N-acetylcysteine appear to be cytoprotective, possibly due to its antioxidant properties. [Projekat Ministarstva nauke Republike Srbije, br. 173014: Molecular mechanisms of redoxsignaling in homeostasis: Adaptation and pathology]

K. Stankov, I. Borišev, V. Kojić, Lazar Rutonjski, G. Bogdanovic, A. Djordjevic

Recent data established the prospective applications for fullerenol (C60(OH)24) nanoparticle (FNP) in many fields, such as antioxidants, neuroprotective agents, and potential anti-radiation drugs. Leukemia cell sensitization to apoptosis induced by ionizing radiation is achieved by upregulation of ROS production and/or downregulation of antioxidative enzymes. Therefore, our aim was to analyze the potential role of fullerenol nanoparticle in modulation of the leukemic cellular response to irradiation. We used the qRT-PCR to analyze the expression level of mRNA for 11 genes in irradiated and FNP pre-treated irradiated K562 cells, and compared the gene expression level with the overall cell survival. Our results of the improved cell survival in FNP-treated irradiated cells and significant overexpression of anti-apoptotic Bcl-2 and Bcl-xL and cytoprotective genes such as GSTA4, MnSOD, NOS, CAT and HO-1 genes, may indicate that FNP exerts cytoprotective function in K562 leukemic cells, rendering K562 cells more tolerant to radiotherapy.

V. Popsavin, Ivana Kovacevic, Goran Benedekovic, Mirjana Popsavin, V. Kojić, G. Bogdanovic

Goniobutenolides A (1) and B (2), crassalactone D (3), 4-epi-crassalactone D (4), and the corresponding 7-epimers have been synthesized starting from d-glucose. The key step in the synthesis of 1 and 2 is a new one-pot sequence comprised of a Z-selective Wittig olefination/lactonization/β-elimination. Preparation of 3 and 4 included the final 5-endo-trig spirocyclization of 1 and 2. The synthesized products were evaluated for their in vitro antiproliferative activity against selected tumor cell lines.

Djordje Veljović, M. Čolić, V. Kojić, G. Bogdanovic, Z. Kojić, Andrijana Banjac, Ē. Palčevskis, R. Petrović et al.

The effect of decreasing the grain size on the biocompatibility, cell-material interface, and mechanical properties of microwave-sintered monophase hydroxyapatite bioceramics was investigated in this study. A nanosized stoichiometric hydroxyapatite powder was isostatically pressed at high pressure and sintered in a microwave furnace in order to obtain fine grained dense bioceramics. The samples sintered at 1200°C, with a density near the theoretical one, were composed of micron-sized grains, while the grain size decreased to 130 nm on decreasing the sintering temperature to 900°C. This decrease in the grain size certainly led to increases in the fracture toughness by much as 54%. An in vitro investigation of biocompatibility with L929 and human MRC-5 fibroblast cells showed noncytotoxic effects for both types of bioceramics, while the relative cell proliferation rate, cell attachment and metabolic activity of the fibroblasts were improved with decreasing of grain size. An initial in vivo investigation of biocompatibility by the primary cutaneous irritation test showed that both materials exhibited no irritation properties.

Evgenija A Djurendić, Jovana J. Ajduković, M. Sakač, J. Csanádi, V. Kojić, G. Bogdanovic, Katarina M. Penov Gaši

B. Gustafsson, E. Honkaniemi, S. Goh, G. Giraud, E. Forestier, U. von Döbeln, T. Allander, T. Dalianis et al.

Background: Neonatal dried blood spots (Guthrie cards) have been used to demonstrate a prenatal origin of clonal leukemia-specific genetic aberrations in several subgroups of childhood acute lymphoblastic leukemia (ALL). One hypothesis suggests that an infectious agent could initiate genetic transformation already in utero. In search for a possible viral agent, Guthrie cards were analyzed for the presence of 3 newly discovered polyomavirus Karolinska Institutet polymavirus (KIPyV), Washington University polyomavirus (WUPyV), and Merkel cell polyomavirus (MCPyV). Methods: Guthrie cards from 50 children who later developed ALL and 100 matched controls were collected and analyzed by standard or real-time polymerase chain reaction for the presence of the VP1 region of KIPyV, WUPyV, and MCPyV, and the LT region for MCPyV. Results and Conclusions: DNA from KIPyV, WUPyV, and MCPyV was not detected in neonatal blood samples from children with ALL or controls. Prenatal infections with these viruses are not likely to be etiological drivers for childhood leukemogenesis.

G. Bogdanovic, S. Ušaj-Knežević, Milena Krajnovic, V. Kojić, Z. Nikin, T. Petrović, K. Krtolica, Mirjana Popsavin et al.

Nema pronađenih rezultata, molimo da izmjenite uslove pretrage i pokušate ponovo!

Pretplatite se na novosti o BH Akademskom Imeniku

Ova stranica koristi kolačiće da bi vam pružila najbolje iskustvo

Saznaj više