Monika Ursinyova

Cadmium, lead and mercury in human milk from Slovakia

The objective of this study was to investigate Cd, Pb, and Hg levels in the breast milk of 158 lactating healthy women who were not occupationally exposed and living in eight environmentally different polluted locations of the Slovak Republic. Levels of these metals were examined in relation to selected parameters, such as: location, mothers age, parity, number of mothers teeth fillings, newborns gender and birth weight, and smoking habits in the family. Cd and Pb levels in human milk and reconstituted infant formula were determined by GFAAS. Hg levels were measured by amalgamation technique AAS. The average concentrations of Cd, Pb and Hg in breast milk samples, taken on the 4th postpartum day, were 0.43, 4.7 and 0.94 µg/kg, respectively, and those in infant formula (n = 10) were 0.40, 5.0 and 0.25 µg/kg, respectively. Dietary weekly intakes of Cd, Pb, and Hg from breast milk and infant formula in newborn babies were also estimated. Whereas the calculated average dietary intakes of Cd, Pb, and Hg in newborn babies from breast milk and infant formula were all far lower than the appropriate PTWI values recommended by WHO/FAO, two individual breast milk samples for Pb and one breast milk sample for Hg exceeded the PTWI values. Regarding the studied parameters, only the active/passive smoking of the mother at home significantly increased Pb levels in breast milk and amalgam teeth fillings increased Hg levels in breast milk.

Maternal amalgam dental fillings as the source of mercury exposure in developing fetus and newborn

Dental amalgam is a mercury-based filling containing approximately 50% of metallic mercury (Hg0). Human placenta does not represent a real barrier to the transport of Hg0; hence, fetal exposure occurs as a result of maternal exposure to Hg, with possible subsequent neurodevelopmental disabilities in infants. This study represents a substudy of the international NIH-funded project “Early Childhood Development and polychlorinated biphenyls Exposure in Slovakia”. The main aim of this analysis was to assess the relationship between maternal dental amalgam fillings and exposure of the developing fetus to Hg. The study subjects were mother–child pairs (N=99). Questionnaires were administered after delivery, and chemical analyses of Hg were performed in the samples of maternal and cord blood using atomic absorption spectrometry with amalgamation technique. The median values of Hg concentrations were 0.63 μg/l (range 0.14–2.9 μg/l) and 0.80 μg/l (range 0.15–2.54 μg/l) for maternal and cord blood, respectively. None of the cord blood Hg concentrations reached the level considered to be hazardous for neurodevelopmental effects in children exposed to Hg in utero (EPA reference dose for Hg of 5.8 μg/l in cord blood). A strong positive correlation between maternal and cord blood Hg levels was found (ρ=0.79; P<0.001). Levels of Hg in the cord blood were significantly associated with the number of maternal amalgam fillings (ρ=0.46, P<0.001) and with the number of years since the last filling (ρ=−0.37, P<0.001); these associations remained significant after adjustment for maternal age and education. Dental amalgam fillings in girls and women of reproductive age should be used with caution, to avoid increased prenatal Hg exposure.

Intracellular uptake of magnetite nanoparticles: A focus on physico-chemical characterization and interpretation of in vitro data

Comprehensive characterization of nanoparticles associated with investigation of their cellular uptake creates the basis on which fundamental in vitro and in vivo studies can be built. In this work, a complex analysis of various surface-modified magnetite nanoparticles in biologically relevant environment is reported and the promotion of incorrect characterization into the results obtained from model biological experiments leading to false conclusions is demonstrated. Via a bottom-up approach from particle characterization by DLS towards interpretation of biological data based on cellular uptake, this work draws attention to the systematic propagation of errors stemming from inaccurate determination of input parameters for DLS, improper selection of particle size distribution, inadequate sampling, unknown colloidal behavior and the omission of fraction of particles complying with the internalization threshold. In addition, cellular uptake depending on the number of treated cells is shown. The definition of cellular uptake efficacy reflecting the size distribution of particles beside their absolute internalization is postulated.

Manganese and copper imbalance in the food chain constituents in relation to Creutzfeldt-Jakob disease

Abstract The objective of the study was to investigate the possible role of manganese and copper (Mn/Cu) imbalance of the food chain in the focally increased occurrence of Creutzfeldt-Jakob disease (CJD). Mn and Cu concentrations in soil, drinking water and foodstuffs collected from households in the region of focal accumulation of CJD patients and the control region were measured by FAAS. Considerably higher Mn/Cu ratios in the studied region than those in the control region were found for soil (49.3 vs. 21.1), honey (8.05 vs. 4.86), and for the main local food items: potatoes (2.09 vs. 1.07) and bread (5.85 vs. 5.35), however, only soil and potatoes were of statistical significance. The results could indicate a rare coincidence of the verified endogenous CJD risk (genetic) with a very probable exogenous CJD risk factor (Mn/Cu dietary/environmental imbalance), but whether and how this coincidence may contribute to the unique, continual temporo-spatial clustering of genetic CJD should be investigated in further studies.

Surface-modified magnetite nanoparticles act as aneugen-like spindle poison

Iron oxide nanoparticles are one of the most promising types of nanoparticles for biomedical applications, primarily in the context of nanomedicine-based diagnostics and therapy; hence, great attention should be paid to their bio-safety. Here, we investigate the ability of surface-modified magnetite nanoparticles (MNPs) to produce chromosome damage in human alveolar A549 cells. Compared to control cells, all the applied MNPs increased the level of micronuclei moderately but did not cause structural chromosomal aberrations in exposed cells. A rise in endoreplication, polyploid and multinuclear cells along with disruption of tubulin filaments, downregulation of Aurora protein kinases and p53 protein activation indicated the capacity of these MNPs to impair the chromosomal passenger complex and/or centrosome maturation. We suppose that surface-modified MNPs may act as aneugen-like spindle poisons via interference with tubulin polymerization. Further studies on experimental animals revealing mechanisms of therapeutic-aimed MNPs are required to confirm their suitability as potential anti-cancer drugs.

WITHDRAWN: Natural polyphenols modify trace element status and improve clinical symptoms of attention-deficit hyperactivity disorder.

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EFFECTS ON THE MENTAL AND MOTOR ABILITIES OF CHILDREN EXPOSED TO LOW LEVELS OF LEAD IN BRATISLAVA

A cross-sectional clinical evaluation was performed on 395 children aged 9-10 yr residing in Bratislava, Republic of Slovakia, to examine the potential adverse effects of low lead levels in blood (PbB) on neuromotor and cognitive performance. Eight clinical evaluations comprised of neuromotor (simple reaction time, Vienna, tapping test) and cognitive tests (Benton, Bender, Raven, and WISC1 and 2) were conducted. Whole blood lead levels served as the surrogate for lead body-burden levels. The mean PbB of the study population was 36.5 ug/L (SD-16.2). A statistically significant negative association between PbB and global intelligence (Raven, p <.001) visual short-term memory (Benton, p <.05), and activity evaluations by teachers and parents ( p <.05) was observed in the study population. Eight covariates were included in a multivariate analysis to examine the confounding effects of socioeconomic factors on the PbB-test performance relationship. A highly significant negative association was observed...