Institute of Medical Research and Occupational Health

Zagreb, Croatia

Institute of Medical Research and Occupational Health

Zagreb, Croatia
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Zeneli L.,University of Prishtina | Sekovanic A.,Institute of Medical Research and Occupational Health | Ajvazi M.,University of Prishtina | Kurti L.,University of Prishtina | Daci N.,University of Prishtina
Environmental Geochemistry and Health | Year: 2016

Humans are exposed to different stress factors that are responsible for over-production of reactive oxygen species. Exposure to heavy metals is one of these factors. The aim of the study was to analyze the effect of chronic exposure to heavy metals through coal flying ash on the efficiency of antioxidative defensive mechanisms, represented by the activity of superoxide dismutase, glutathione peroxidase and ascorbic acid. Nonessential elements such as arsenic and mercury levels showed a significant increase (p > 0.001) in the power plant workers rather than in the control subjects. There were no significant differences of blood cadmium between power plant workers and control subjects. We found a significant positive correlation (p < 0.05) between BAs/SZn (r = 0.211), BAs/BSe (r = 0.287), BCd/SCu (r = 0.32) and BHg/BSe (r = 0.263) in the plant workers. Red blood cell antioxidant enzymes and plasma ascorbic acid were significantly lower in power plants workers than in the control group (p < 0.002). We can conclude that levels of mercury, arsenic and cadmium in blood, despite their concentration within the reference values, significantly affect plasma ascorbic acid concentration, superoxide dismutase and glutathione peroxidase activity, which are able to increase the risk of oxidative stress. © 2015, Springer Science+Business Media Dordrecht.


Segvic Klaric M.,University of Zagreb | Jaksic Despot D.,University of Zagreb | Kopjar N.,Institute of Medical Research and Occupational Health | Rasic D.,Institute of Medical Research and Occupational Health | And 3 more authors.
Ecotoxicology and Environmental Safety | Year: 2015

Aspergillus sclerotiorum (AS) is a well-known producer of ochratoxin A (OTA) while Aspergillus pseudoglaucus (AP) produces a wide range of extrolites with poorly investigated toxicity. These species are frequently co-occur in grain mill aeromycota. The aim of this study was to determine OTA levels in spore extracts using HPLC and immunoaffinity columns, and to examine the cytotoxicity of pure OTA, OTA-positive (AS-OTA(+)) and OTA-negative (AS-OTA(-)) spore extracts, as well as of AP spore extract, on human lung adenocarcinoma cells A549, individually and in combination, using a colorimetric MTT test (540nm). To establish which type of cell death predominated after treatments, a quantitative fluorescent assay with ethidium bromide and acridine orange was used, and the level of primary DNA damage in A549 cells was evaluated using the alkaline comet assay. OTA was detected in spore extracts (0.3-28μg/mL) of 3/6 of the AS strains, while none of the tested AP strains were able to produce OTA. Taking into account the maximum detected concentration of OTA in the spores, the daily intake of OTA by inhalation was calculated to be 1ng/kg body weight (b.w.), which is below the tolerable daily intake for OTA (17ng/kg b.w.). Using the MTT test, the following IC50 values were obtained: single OTA (53μg/mL); AS-OTA(+) (mass concentration 934μg/mL corresponds to 10.5μg/mL of OTA in spore extract); and 2126μg/mL for AP. The highest applied concentration of AS-OTA(-) spore extract (4940μg/mL) decreased cell viability by 30% and IC50 for the extract could not be determined. Single OTA and AS-OTA(+) and combinations (AP+AS-OTA(+) and AP+AS-OTA(-)) in subtoxic concentrations provoked significant primary DNA damage, apoptosis, and to a lesser extent, necrosis in A549 cells. Mixture of AP+AS-OTA(+) and AP+AS-OTA(-) in subtoxic concentrations showed dominant additive interactions. Despite the low calculated daily intake of OTA by inhalation, our results suggest that chronic exposure to high levels of OTA-producing airborne fungi in combination with other more or less toxic moulds pose a significant threat to human health due to their possible additive and/or synergistic interactions. © 2015 Elsevier Inc.


Beer-Ljubic B.,University of Zagreb | Aladrovic J.,University of Zagreb | Milinkovic-Tur S.,University of Zagreb | Lazarus M.,Institute of Medical Research and Occupational Health | Pusic I.,Ministry of Environmental Protection
Archiv fur Tierzucht | Year: 2012

The aim of the study was to assess the effect of organic selenium dietary supplementation on serum and tissue lipid composition after fattening period and after 48 h fasting in fattening chicken. The study was performed in the Ross hybrid line chicken divided into two groups: control group fed standard diet and Sel Plex group fed standard diet supplemented with 0.3 ppm organic selenium. Blood, liver, intestine and adipose tissue samples were taken upon fattening completion and after 48 h fasting. Total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, triacylglycerol and lipoprotein concentrations were determined in serum, whereas total and free cholesterol, triacylglycerol, lipid peroxide and selenium concentrations and glutathione peroxidase activity (GSH-Px) were determined in tissue samples. During fattening period, the correlation of organic selenium with lipid metabolism manifested as decreased concentrations of serum triacylglycerols and very-low-density lipoprotein (VLDL) (P<0.05), liver triacylglycerols (P<0.05), adipose tissue cholesterol (P<0.05) and small intestine cholesterol (P<0.05), and reduced lipid peroxidation (P<0.05). Upon chicken exposure to 48 h fasting, organic selenium supplementation resulted in increased free cholesterol concentration in adipose tissue (P<0.05), GSH-Px activity in the liver (P<0.05), and selenium (P<0.05) accumulation in the liver. © Leibniz Institute for Farm Animal Biology, Dummerstorf, Germany.


Klaric M.S.,University of Zagreb | Darabos D.,University of Zagreb | Rozgaj R.,Institute of Medical Research and Occupational Health | Kasuba V.,Institute of Medical Research and Occupational Health | Pepeljnjak S.,University of Zagreb
Archives of Toxicology | Year: 2010

This study was aimed at investigating the genotoxic potential of single beauvericin (BEA) and ochratoxin A (OTA) as well as their interaction in porcine kidney epithelial PK15 cells and human leukocytes using the alkaline comet assay. IC50 of BEA (5.0 ± 0.6) and OTA (15.8 ± 1.5) estimated by MTT reduction assay shows that BEA is three times more toxic than OTA. BEA (0.1 and 0.5 μM) and OTA (1 and 5 μM) were applied alone or in combination of these concentrations for 1 and 24 h in PK15 cells and human leukocytes. Genotoxicity of these toxins to PK15 cells was time- and concentration dependent. After 1 h, significant increase in tail length, tail intensity, tail moment, and abnormal sized tails (AST) was noted upon exposure to 1 μM of OTA alone and BEA + OTA combinations. Single BEA (0.5 μM) and OTA (1 and 5 μM) and their combinations evoked significant DNA damage in PK15 cells, considering all comet tail parameters measured after 24 h of treatment. Human leukocytes were slightly concentration but not time dependent. After 1 h of exposure, there were no significant changes in the tail length. Tail intensity, tail moment, and/or incidence of AST were significantly higher in cells treated with single OTA or BEA and their combinations than in control cells. DNA damage in leukocytes was significantly higher after 24 h of exposure to single toxins and their combinations, considering all comet tail parameters, but these changes were less pronounced than in PK15 cells. Combined toxins showed additive and synergistic effects in PK15 cells, while only additive effects were observed in human leukocytes. Combined prolonged exposure to BEA and OTA in subcytotoxic concentrations through food consumption could induce DNA damage contributing to the carcinogenicity in animals and humans. © 2010 Springer-Verlag.


Klaric M.S.,University of Zagreb | Zeljezic D.,Institute of Medical Research and Occupational Health | Rumora L.,University of Zagreb | Peraica M.,Institute of Medical Research and Occupational Health | And 3 more authors.
Archives of Toxicology | Year: 2012

The aim of this study was to establish the involvement of calcium signalling in genotoxicity, apoptosis and necrosis evoked by ochratoxin A (OTA) and citrinin (CTN) alone or in combination in porcine kidney PK15 cells. Cell proliferation test (MTT) and trypan blue assays (24 h) demonstrated that CTN (IC 50 = 73.5 ± 1.0, 75.4 ± 1.4 μM, respectively) was less toxic than OTA (IC 50 = 14.0 ± 2.4, 20.5 ± 1.0 μM, respectively). To test their cytotoxic interactions, two doses of single OTA (6 and 10 μM) and CTN (30 and 50 μM) and their combinations were applied. Combined treatment showed additive cytotoxic effects. OTA and CTN induced dose-dependent increase in cytosolic calcium level (assessed with Fura-2 AM). However, combined treatment did not provoke additional increase in calcium signal. The rate of apoptosis and necrosis (DAPI-antifade staining) was significantly higher after 12 h than 24 h, while the frequencies of micronuclei (MNs) and nuclear buds (NBs) were higher after 24 h than 12 h treatment. Combined exposure resulted in apoptotic and necrotic synergism, while genotoxic effects of OTA + CTN were noted as antagonistic or additive. Co-exposure of cells to calcium chelator BAPTA-AM significantly reduced CTN and OTA + CTN-evoked apoptosis. Twenty-four hour after co-exposure to BAPTA-AM and a single OTA and CTN, MNs significantly decreased while NBs dropped significantly after co-treatment with BAPTA-AM and OTA + CTN. In conclusion, disturbance of Ca 2+ homeostasis caused by OTA and CTN plays a significant role in cell genotoxicity and death. © 2011 Springer-Verlag.


Matic-Skoko S.,Croatian Institute Of Oceanography And Fisheries | Ferri J.,University of Split | Tutman P.,Croatian Institute Of Oceanography And Fisheries | Skaramuca D.,University of Dubrovnik | And 4 more authors.
Marine Biology Research | Year: 2012

This study determined basic biological data for the European conger eel Conger conger (L.) population in the coastal waters of the eastern Adriatic Sea. Juveniles and immature females dominated the coastal population, whereas males were relatively uncommon. The population structure determined by the study suggested spatial separation of sexes and spawning grounds in deeper waters. Both edge-type and marginal increment analyses confirmed the formation of a single growth annulus per year on the ground otoliths. The observed maximum age of the coastal conger eels was 8 years, although most of the sampled fish were 5 years old. The estimated parameters of the von Bertalanffy growth model suggested that the growth of the conger eels was relatively slow. C. conger is an opportunistic predator. Its diet was composed primarily of fishes, followed by crustaceans and cephalopods. Due to the evident site fidelity of the species, the wide prey spectrum of the conger eels (33 taxa) reflected the local benthic community structure. © 2012 Copyright Taylor and Francis Group, LLC.


Zeneli L.,University of Prishtina | Sekovanic A.,Institute of Medical Research and Occupational Health | Daci N.,University of Prishtina
Journal of Environmental Science and Health - Part A Toxic/Hazardous Substances and Environmental Engineering | Year: 2015

This study aimed to evaluate the influence of exposure to aluminum, nickel, thallium and uranium on the metabolism of essential elements in humans, as well as the relationship between uranium, thallium, nickel, and aluminum and essential elements (Ca, Mg, Zn, Se, Mn, Co, Cr, and Mo) in the whole blood and blood serum of healthy men who were occupationally exposed. This study included 97 healthy men, 31-64 years age, including 70 workers in a thermo power plant and 27 control subjects. The results showed that chronic, moderate exposure of trace elements (Al, Ni, Tl, and U) lead to decreased serum chromium (SCr) and blood molybdenum levels (BMo), whereas by the results achieved in terms of correlations between non-essential and essential elements, non-essential elements such as uranium, thallium, nickel, and aluminum, despite their concentration within the reference values, are strongly competitive with essential elements in biochemical processes. Copyright © Taylor & Francis Group, LLC.


PubMed | University of Prishtina and Institute of Medical Research and Occupational Health
Type: Journal Article | Journal: Environmental geochemistry and health | Year: 2016

Humans are exposed to different stress factors that are responsible for over-production of reactive oxygen species. Exposure to heavy metals is one of these factors. The aim of the study was to analyze the effect of chronic exposure to heavy metals through coal flying ash on the efficiency of antioxidative defensive mechanisms, represented by the activity of superoxide dismutase, glutathione peroxidase and ascorbic acid. Nonessential elements such as arsenic and mercury levels showed a significant increase (p>0.001) in the power plant workers rather than in the control subjects. There were no significant differences of blood cadmium between power plant workers and control subjects. We found a significant positive correlation (p<0.05) between BAs/SZn (r=0.211), BAs/BSe (r=0.287), BCd/SCu (r=0.32) and BHg/BSe (r=0.263) in the plant workers. Red blood cell antioxidant enzymes and plasma ascorbic acid were significantly lower in power plants workers than in the control group (p<0.002). We can conclude that levels of mercury, arsenic and cadmium in blood, despite their concentration within the reference values, significantly affect plasma ascorbic acid concentration, superoxide dismutase and glutathione peroxidase activity, which are able to increase the risk of oxidative stress.


PubMed | Institute of Medical Research and Occupational Health, University of Zagreb and University of Szeged
Type: | Journal: Ecotoxicology and environmental safety | Year: 2015

Aspergillus sclerotiorum (AS) is a well-known producer of ochratoxin A (OTA) while Aspergillus pseudoglaucus (AP) produces a wide range of extrolites with poorly investigated toxicity. These species are frequently co-occur in grain mill aeromycota. The aim of this study was to determine OTA levels in spore extracts using HPLC and immunoaffinity columns, and to examine the cytotoxicity of pure OTA, OTA-positive (AS-OTA(+)) and OTA-negative (AS-OTA(-)) spore extracts, as well as of AP spore extract, on human lung adenocarcinoma cells A549, individually and in combination, using a colorimetric MTT test (540nm). To establish which type of cell death predominated after treatments, a quantitative fluorescent assay with ethidium bromide and acridine orange was used, and the level of primary DNA damage in A549 cells was evaluated using the alkaline comet assay. OTA was detected in spore extracts (0.3-28g/mL) of 3/6 of the AS strains, while none of the tested AP strains were able to produce OTA. Taking into account the maximum detected concentration of OTA in the spores, the daily intake of OTA by inhalation was calculated to be 1ng/kg body weight (b.w.), which is below the tolerable daily intake for OTA (17ng/kg b.w.). Using the MTT test, the following IC50 values were obtained: single OTA (53g/mL); AS-OTA(+) (mass concentration 934g/mL corresponds to 10.5g/mL of OTA in spore extract); and 2126g/mL for AP. The highest applied concentration of AS-OTA(-) spore extract (4940g/mL) decreased cell viability by 30% and IC50 for the extract could not be determined. Single OTA and AS-OTA(+) and combinations (AP+AS-OTA(+) and AP+AS-OTA(-)) in subtoxic concentrations provoked significant primary DNA damage, apoptosis, and to a lesser extent, necrosis in A549 cells. Mixture of AP+AS-OTA(+) and AP+AS-OTA(-) in subtoxic concentrations showed dominant additive interactions. Despite the low calculated daily intake of OTA by inhalation, our results suggest that chronic exposure to high levels of OTA-producing airborne fungi in combination with other more or less toxic moulds pose a significant threat to human health due to their possible additive and/or synergistic interactions.

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