Publications by authors named "Zbynek Vecera"

23 Publications

  • Page 1 of 1

A Clearance Period after Soluble Lead Nanoparticle Inhalation Did Not Ameliorate the Negative Effects on Target Tissues Due to Decreased Immune Response.

Int J Mol Sci 2020 Nov 19;21(22). Epub 2020 Nov 19.

Laboratory of Molecular Morphogenesis, Institute of Animal Physiology and Genetics, v.v.i., Czech Academy of Sciences, 602 00 Brno, Czech Republic.

The inhalation of metal (including lead) nanoparticles poses a real health issue to people and animals living in polluted and/or industrial areas. In this study, we exposed mice to lead(II) nitrate nanoparticles [Pb(NO) NPs], which represent a highly soluble form of lead, by inhalation. We aimed to uncover the effects of their exposure on individual target organs and to reveal potential variability in the lead clearance. We examined (i) lead biodistribution in target organs using laser ablation and inductively coupled plasma mass spectrometry (LA-ICP-MS) and atomic absorption spectrometry (AAS), (ii) lead effect on histopathological changes and immune cells response in secondary target organs and (iii) the clearance ability of target organs. In the lungs and liver, Pb(NO) NP inhalation induced serious structural changes and their damage was present even after a 5-week clearance period despite the lead having been almost completely eliminated from the tissues. The numbers of macrophages significantly decreased after 11-week Pb(NO) NP inhalation; conversely, abundance of alpha-smooth muscle actin (α-SMA)-positive cells, which are responsible for augmented collagen production, increased in both tissues. Moreover, the expression of nuclear factor κB () and selected cytokines, such as tumor necrosis factor alpha (), transforming growth factor beta 1 (), interleukin 6(), and , displayed a tissue-specific response to lead exposure. In summary, diminished inflammatory response in tissues after Pb(NO) NPs inhalation was associated with prolonged negative effect of lead on tissues, as demonstrated by sustained pathological changes in target organs, even after long clearance period.
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http://dx.doi.org/10.3390/ijms21228738DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7699374PMC
November 2020

Interaction of Cucurbit[7]uril with Oxime K027, Atropine, and Paraoxon: Risky or Advantageous Delivery System?

Int J Mol Sci 2020 Oct 23;21(21). Epub 2020 Oct 23.

Department of Clinical Biochemistry and Diagnostics, University Hospital and Faculty of Medicine Hradec Kralove, 50002 Hradec Kralove, Czech Republic.

Antidotes against organophosphates often possess physicochemical properties that mitigate their passage across the blood-brain barrier. Cucurbit[7]urils may be successfully used as a drug delivery system for bisquaternary oximes and improve central nervous system targeting. The main aim of these studies was to elucidate the relationship between cucurbit[7]uril, oxime K027, atropine, and paraoxon to define potential risks or advantages of this delivery system in a complex in vivo system. For this reason, in silico (molecular docking combined with umbrella sampling simulation) and in vivo (UHPLC-pharmacokinetics, toxicokinetics; acetylcholinesterase reactivation and functional observatory battery) methods were used. Based on our results, cucurbit[7]urils affect multiple factors in organophosphates poisoning and its therapy by (i) scavenging paraoxon and preventing free fraction of this toxin from entering the brain, (ii) enhancing the availability of atropine in the central nervous system and by (iii) increasing oxime passage into the brain. In conclusion, using cucurbit[7]urils with oximes might positively impact the overall treatment effectiveness and the benefits can outweigh the potential risks.
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http://dx.doi.org/10.3390/ijms21217883DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7672622PMC
October 2020

Subchronic continuous inhalation exposure to zinc oxide nanoparticles induces pulmonary cell response in mice.

J Trace Elem Med Biol 2020 Apr 6;61:126511. Epub 2020 Apr 6.

Laboratory of Neurobiology and Pathological Physiology, Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Veveří 967/97, 602 00, Brno, Czech Republic; Laboratory of Neurobiology and Molecular Psychiatry, Department of Biochemistry, Faculty of Science, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic. Electronic address:

Objectives: We used mice as an animal model to investigate the entry of ZnO nanoparticles from the ambient air into the lungs and other organs, subsequent changes in Zn levels and the impact on the transcription of Zn homeostasis-related genes in the lungs.

Methods: The mice were exposed to two concentrations of ZnO nanoparticles; lower (6.46 × 10 particles/cm) and higher (1.93 × 10 particles/cm), allowed to breathe the nanoparticles in the air for 12 weeks and subjected to necropsy. Characterization of the ZnO nanoparticles was done using transmission electron microscopy (TEM). Energy-dispersive X-ray (EDX) spectroscopy was used to quantify ZnO nanoparticles in the lungs, brain, liver and kidney. The total zinc content in the lungs, brain, liver, kidney, red blood cells and plasma was estimated by inductively coupled plasma mass spectroscopy (ICP-MS). Transcription rate of the genes was evaluated by RealTime PCR.

Results: The two concentration of ZnO nanoparticles in the ambient air produced two different outcomes. The lower concentration resulted in significant increases in Zn content of the liver while the higher concentration significantly increased Zn in the lungs (p < 0.05). Additionally, at the lower concentration, Zn content was found to be lower in brain tissue (p < 0.05). Using TEM/EDX we detected ZnO nanoparticles inside the cells in the lungs, kidney and liver. Inhaling ZnO NP at the higher concentration increased the levels of mRNA of the following genes in the lungs: Mt2 (2.56 fold), Slc30a1 (1.52 fold) and Slc30a5 (2.34 fold). At the lower ZnO nanoparticle concentration, only Slc30a7 mRNA levels in the lungs were up (1.74 fold). Thus the two air concentrations of ZnO nanoparticles produced distinct effects on the expression of the Zn-homeostasis related genes.

Conclusion: Until adverse health effects of ZnO nanoparticles deposited in organs such as lungs are further investigated and/or ruled out, the exposure to ZnO nanoparticles in aerosols should be avoided or minimised.
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http://dx.doi.org/10.1016/j.jtemb.2020.126511DOI Listing
April 2020

Gene Expression and Epigenetic Changes in Mice Following Inhalation of Copper(II) Oxide Nanoparticles.

Nanomaterials (Basel) 2020 Mar 18;10(3). Epub 2020 Mar 18.

Department of Genetic Toxicology and Epigenetics, Institute of Experimental Medicine of the Czech Academy of Sciences, 14220 Prague, Czech Republic.

We investigated the transcriptomic response and epigenetic changes in the lungs of mice exposed to inhalation of copper(II) oxide nanoparticles (CuO NPs) (8 × 10 NPs/m) for periods of 3 days, 2 weeks, 6 weeks, and 3 months. A whole genome transcriptome and miRNA analysis was performed using next generation sequencing. Global DNA methylation was assessed by ELISA. The inhalation resulted in the deregulation of mRNA transcripts: we detected 170, 590, 534, and 1551 differentially expressed transcripts after 3 days, 2 weeks, 6 weeks, and 3 months of inhalation, respectively. Biological processes and pathways affected by inhalation, differed between 3 days exposure (collagen formation) and longer treatments (immune response). Periods of two weeks exposure further induced apoptotic processes, 6 weeks of inhalation affected the cell cycle, and 3 months of treatment impacted the processes related to cell adhesion. The expression of miRNA was not affected by 3 days of inhalation. Prolonged exposure periods modified miRNA levels, although the numbers were relatively low (17, 18, and 38 miRNAs, for periods of 2 weeks, 6 weeks, and 3 months, respectively). Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways analysis based on miRNA-mRNA interactions, revealed the deregulation of processes implicated in the immune response and carcinogenesis. Global DNA methylation was not significantly affected in any of the exposure periods. In summary, the inhalation of CuO NPs impacted on both mRNA and miRNA expression. A significant transcriptomic response was already observed after 3 days of exposure. The affected biological processes and pathways indicated the negative impacts on the immune system and potential role in carcinogenesis.
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http://dx.doi.org/10.3390/nano10030550DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7153614PMC
March 2020

Variability in the Clearance of Lead Oxide Nanoparticles Is Associated with Alteration of Specific Membrane Transporters.

ACS Nano 2020 03 4;14(3):3096-3120. Epub 2020 Mar 4.

Laboratory of Molecular Morphogenesis, Institute of Animal Physiology and Genetics, v.v.i., Czech Academy of Sciences, Brno 602 00, Czech Republic.

Lead oxide nanoparticles (PbONPs), upon their entry into the lungs inhalation, induce structural changes in primary and secondary target organs. The fate and ultrastructural localization of PbONPs in organs is known to be dependent on the specific organ. Here, we focused on the differences in the ability to clear the inhaled PbONPs from secondary target organs and on molecular and cellular mechanisms contributing to nanoparticle removal. Mice were exposed to PbONPs in whole-body inhalation chambers. Clearance of ionic lead and PbONPs (Pb/PbONPs) from the lungs and liver was very effective, with the lead being almost completely eliminated from the lungs and the physiological state of the lung tissue conspicuously restored. Kidneys exposed to nanoparticles did not exhibit serious signs of damage; however, LA-ICP-MS uncovered a certain amount of lead located preferentially in the kidney cortex even after a clearance period. The concentration of lead in femurs, as representatives of the axial skeleton, was the highest among studied organs at all designated time points after PbONP exposure, and the clearance ability of lead from the femurs was very low in contrast to other organs. The organ-specific increase of ABC transporters expression (ABCG2 in lungs and ABCC3 in the liver) was observed in exposed animals, suggesting their involvement in removing Pb/PbONPs from tissues. Moreover, the expression of and displayed a tissue-specific response to lead exposure. Our results uncovered high variability among the organs in their ability to clear Pb/PbONPs and in the transporters involved in this process.
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http://dx.doi.org/10.1021/acsnano.9b08143DOI Listing
March 2020

The effects of nano-sized PbO on biomarkers of membrane disruption and DNA damage in a sub-chronic inhalation study on mice.

Nanotoxicology 2020 03 15;14(2):214-231. Epub 2019 Nov 15.

Faculty of Science, RECETOX, Masaryk University, Brno, Czech Republic.

Although the production of engineered nanoparticles increases our knowledge of toxicity and mechanisms of bioactivity during relevant exposures is lacking. In the present study mice were exposed to PbO nanoparticles (PbONP; 192.5 µg/m; 1.93 × 10 particles/cm) for 2, 5 and 13 weeks through continuous inhalation. The analyses addressed Pb and PbONP distribution in organs (lung, liver, kidney, brain) using electrothermal atomic absorption spectrometry and transmission electron microscopy, as well as histopathology and analyses of oxidative stress biomarkers. New LC-MS/MS methods were validated for biomarkers of lipid damage F2-isoprostanes (8-iso-prostaglandins F and E) and hydroxylated deoxoguanosine (8-OHdG, marker of DNA oxidation). Commonly studied malondialdehyde was also measured as TBARS by HPLC-DAD. The study revealed fast blood transport and distribution of Pb from the lung to the kidney and liver. A different Pb accumulation trend was observed in the brain, suggesting transfer of NP along the nasal nerve to the olfactory bulbs. Long-term inhalation of PbONP caused lipid peroxidation in animal brains (increased levels of TBARS and both isoprostanes). Membrane lipid damage was also detected in the kidney after shorter exposures, but not in the liver or lung. On the contrary, longer exposures to PbONP increased levels of 8-OHdG in the lung and temporarily increased lung weight after 2 and 5 weeks of exposure. The histopathological changes observed mainly in the lung and liver indicated inflammation and general toxicity responses. The present long-term inhalation study indicates risks of PbONP to both human health and the environment.
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http://dx.doi.org/10.1080/17435390.2019.1685696DOI Listing
March 2020

Six-week inhalation of CdO nanoparticles in mice: The effects on immune response, oxidative stress, antioxidative defense, fibrotic response, and bones.

Food Chem Toxicol 2020 Feb 9;136:110954. Epub 2019 Nov 9.

Institute of Analytical Chemistry of Czech Academy of Sciences, Veveri 97, 60200, Brno, Czech Republic.

Due to the growing number of applications of cadmium oxide nanoparticles (CdO NPs), there is a concern about their potential deleterious effects. The objective of our study was to investigate the effect of CdO NPs on the immune response, renal and intestine oxidative stress, blood antioxidant defence, renal fibrotic response, bone density and mineral content. Six-week-old female ICR mice were exposed to CdO NPs for 6 weeks by inhalation (particle size: 9.82 nm, mass concentration: 31.7 μg CdO/m, total deposited dose: 0.195 μg CdO/g body weight). CdO NPs increased percentage of thymus CD3eCD8a cells and moderately enhanced splenocyte proliferation and production of cytokines and chemokines. CdO NPs elevated pro-fibrotic factors (TGF-β2, α-SMA and collagen I) in the kidney, and concentrations of AGEs in the intestine. The ratio of GSH and GSSG in blood was slightly reduced. Exposure to CdO NPs resulted in 10-fold higher Cd concentration in tibia bones. No differences were found in bone mass density, mineral content, bone area values, bone concentrations of Ca, P, Mg and Ca/P ratio. Our findings indicate stimulation of immune/inflammatory response, oxidative stress in the intestine, starting fibrotic response in kidneys and accumulation of CdO NPs in bones of mice.
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http://dx.doi.org/10.1016/j.fct.2019.110954DOI Listing
February 2020

Temperature alters susceptibility of Picea abies seedlings to airborne pollutants: The case of CdO nanoparticles.

Environ Pollut 2019 Oct 13;253:646-654. Epub 2019 Jul 13.

Global Change Research Institute of the Czech Academy of Sciences, Bělidla 986/4a, CZ-603 00, Brno, Czech Republic. Electronic address:

Although plants are often exposed to atmospheric nanoparticles (NPs), the mechanism of NP deposition and their effects on physiology and metabolism, and particularly in combination with other stressors, are not yet understood. Exploring interactions between stressors is particularly important for understanding plant responses in urban environments where elevated temperatures can be associated with air pollution. Accordingly, 3-year-old spruce seedlings were exposed for 2 weeks to aerial cadmium oxide (CdO) NPs of environmentally relevant size (8-62 nm) and concentration (2 × 10 cm). While half the seedlings were initially acclimated to high temperature (35 °C) and vapour pressure deficit (VPD; 2.81 kPa), the second half of the plants were left under non-stressed conditions (20 °C, 0.58 kPa). Atomic absorption spectrometry was used to determine Cd content in needles, while gas and liquid chromatography was used to determine changes in primary and secondary metabolites. Photosynthesis-related processes were explored with gas-exchange and chlorophyll fluorescence systems. Our work supports the hypothesis that atmospheric CdO NPs penetrate into leaves but high temperature and VPD reduce such penetration due to stomatal closure. The hypothesis that atmospheric CdO NPs influences physiological and metabolic processes in plants was also confirmed. This impact strengthens with increasing time of exposure. Finally, we found evidence that plants acclimated to stress conditions have different sensitivity to CdO NPs compared to plants not so acclimated. These findings have important consequences for understanding impacts of global warming on plants and indicates that although the effects of elevated temperatures can be deleterious, this may limit other forms of plant stress associated with air pollution.
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http://dx.doi.org/10.1016/j.envpol.2019.07.061DOI Listing
October 2019

A murine model of the effects of inhaled CuO nanoparticles on cells of innate and adaptive immunity - a kinetic study of a continuous three-month exposure.

Nanotoxicology 2019 09 23;13(7):952-963. Epub 2019 Apr 23.

Department of Genetic Toxicology and Nanotoxicology, Institute of Experimental Medicine of the Czech Academy of Sciences , Prague , Czech Republic.

The inhalation or application of nanoparticles (NPs) has serious impacts on immunological reactivity. However, the effects of NPs on the immune system are influenced by numerous factors, which cause a high variability in the results. Here, mice were exposed to a three month continuous inhalation of copper oxide (CuO) NPs, and at different time intervals (3, 14, 42 and 93 days), the composition of cell populations of innate and adaptive immunity was evaluated in the spleen by flow cytometry. The ability of spleen cells from exposed and control mice to respond to stimulation with T- or B-cell mitogens by proliferation and by production of cytokines IL-2, IL-6, IL-10, IL-17 and IFN-γ was characterized. The results showed that the inhalation of CuO NPs predominantly affects the cells of innate immunity (changes in the proportion of eosinophils, neutrophils, macrophages and antigen-presenting cells) with a minimal effect on the percentage of T and B lymphocytes. However, the proliferative and secretory activity of T cells was already significantly enhanced after 3 days from the start of inhalation, decreased on day 14 and normalized at the later time intervals. There was no correlation between the impacts of NPs on the cells of innate and adaptive immunity. The results have shown that the inhalation of CuO NPs significantly alters the composition of cell populations of innate immunity and modulates the proliferation and production of cytokines by cells of the adaptive immune system. However, the immunomodulatory effects of inhaled NPs strongly depend on the time of inhalation.
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http://dx.doi.org/10.1080/17435390.2019.1602679DOI Listing
September 2019

Inhalation of ZnO Nanoparticles: Splice Junction Expression and Alternative Splicing in Mice.

Toxicol Sci 2019 03;168(1):190-200

*Department of Genetic Toxicology and Nanotoxicology, Institute of Experimental Medicine of the Czech Academy of Sciences, Prague 14220, Czech Republic.

Despite the wide application of nanomaterials, toxicity studies of nanoparticles (NP) are often limited to in vitro cell models, and the biological impact of NP exposure in mammals has not been thoroughly investigated. Zinc oxide (ZnO) NPs are commonly used in various consumer products. To evaluate the effects of the inhalation of ZnO NP in mice, we studied splice junction expression in the lungs as a proxy to gene expression changes analysis. Female ICR mice were treated with 6.46 × 104 and 1.93 × 106 NP/cm3 for 3 days and 3 months, respectively. An analysis of differential expression and alternative splicing events in 298 targets (splice junctions) of 68 genes involved in the processes relevant to the biological effects of ZnO NP was conducted using next-generation sequencing. Three days of exposure resulted in the upregulation of IL-6 and downregulation of BID, GSR, NF-kB2, PTGS2, SLC11A2, and TXNRD1 splice junction expression; 3 months of exposure increased the expression of splice junctions in ALDH3A1, APAF1, BID, CASP3, DHCR7, GCLC, GCLM, GSR, GSS, EHHADH, FAS, HMOX-1, IFNγ, NF-kB1, NQO-1, PTGS1, PTGS2, RAD51, RIPK2, SRXN1, TRAF6, and TXNRD1. Alternative splicing of TRAF6 and TXNRD1 was induced after 3 days of exposure to 1.93 × 106 NP/cm3. In summary, we observed changes of splice junction expression in genes involved in oxidative stress, apoptosis, immune response, inflammation, and DNA repair, as well as the induction of alternative splicing in genes associated with oxidative stress and inflammation. Our data indicate the potential negative biological effects of ZnO NP inhalation.
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http://dx.doi.org/10.1093/toxsci/kfy288DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6390655PMC
March 2019

Aerosol sampler for analysis of fine and ultrafine aerosols.

Anal Chim Acta 2018 Aug 10;1020:123-133. Epub 2018 Mar 10.

Institute of Analytical Chemistry of the Czech Academy of Sciences, v.v.i., Veveří 97, 602 00 Brno, Czech Republic.

A new aerosol sampler based on the original version of Aerosol Counterflow Two-Jets Unit (ACTJU) is described. The ACTJU collector, connected with a water-based Condensation Growth Unit (CGU) placed upstream of the ACTJU, accomplished the quantitative collection of fine and ultrafine aerosol particles down to a few nanometers in diameter. Condensation of water vapor in the CGU enlarges nanometer sized particles to larger sizes in the supermicrometer range and the formed droplets are then collected into water in the ACTJU collector. The continuous collection of aerosols with the CGU-ACTJU sampler allows for the time-resolved measurement of changes in the concentration of particulate constituents. Coupling of the CGU-ACTJU sampler with on-line detection devices allows in-situ automated analysis of water-soluble aerosol components with high time resolution of 1 s (e.g., FIA detection for nitrite or nitrate) or 1 h (e.g., IC detection with preconcentration step for inorganic anions). Under the optimum conditions (the air flow rate of 10 L min and water flow rate of 1.5 mL min), the limit of detection (IC including the preconcentration) for particulate fluoride, chloride, nitrite, nitrate, sulphate and phosphate is 2.53, 6.64, 24.2, 16.8, 0.12 and 5.03 ng m, respectively. The apparatus is sufficiently robust for its application at routine monitoring of aerosol composition in real-time.
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http://dx.doi.org/10.1016/j.aca.2018.02.070DOI Listing
August 2018

Changes of primary and secondary metabolites in barley plants exposed to CdO nanoparticles.

Environ Pollut 2016 Nov 6;218:207-218. Epub 2016 Aug 6.

Laboratory of Ecological Plant Physiology, Global Change Research Institute of the Czech Academy of Sciences, v.v.i., Bělidla 986/4a, CZ-603 00 Brno, Czech Republic. Electronic address:

The environmental fate of airborne nanoparticles and their toxicity to plants is not yet fully understood. Pot-grown barley plants with second leaves developed were therefore exposed to CdO nanoparticles (CdONPs) of ecologically relevant size (7-60 nm) and concentration (2.03 ± 0.45 × 10 particles cm) in air for 3 weeks. An experiment was designed to test the effects of different treatments when only leaves (T1); leaves and soil substrate (T2); and leaves, soil, and water supply were exposed to nanoparticles (T3). A fourth, control group of plants was left without treatment (T0). Although CdONPs were directly absorbed by leaves from the air, a part of leaf-allocated Cd was also transported from roots by transpiration flow. Chromatographic assays revealed that CdONPs had a significant effect on total content of primary metabolites (amino acids and saccharides) but no significant effect on total content of secondary metabolites (phenolic compounds, Krebs cycle acids, and fatty acids). In addition, the compositions of individual metabolite classes were affected by CdONP treatment. For example, tryptophan and phenylalanine were the most affected amino acids in both analysed organs, while ferulic acid and isovitexin constituted the polyphenols most affected in leaves. Even though CdONP treatment had no effect on total fatty acids content, there were significant changes in the composition of saturated and unsaturated fatty acids in both the roots and leaves of treated plants. Although the results indicate the most pronounced effect in T3 plants as compared to T1 and T2 plants, even just leaf exposure to CdONPs has the potential to induce changes in plant metabolism.
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http://dx.doi.org/10.1016/j.envpol.2016.05.013DOI Listing
November 2016

WITHDRAWN: Wet effluent diffusion denuder: The tool for determination of monoterpenes in forest.

Talanta 2016 09 17;158:192. Epub 2015 Dec 17.

Institute of Analytical Chemistry of the CAS, v. v. i., Veveří 97, 60200 Brno, Czech Republic.

The Publisher regrets that this article is an accidental duplication of an article that has already been published, 10.1016/j.talanta.2016.03.032. The duplicate article has therefore been withdrawn.The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.
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http://dx.doi.org/10.1016/j.talanta.2015.12.041DOI Listing
September 2016

Inhaled Cadmium Oxide Nanoparticles: Their in Vivo Fate and Effect on Target Organs.

Int J Mol Sci 2016 Jun 3;17(6). Epub 2016 Jun 3.

Institute of Animal Physiology and Genetics, v.v.i., Czech Academy of Sciences, Brno 602 00, Czech Republic.

The increasing amount of heavy metals used in manufacturing equivalently increases hazards of environmental pollution by industrial products such as cadmium oxide (CdO) nanoparticles. Here, we aimed to unravel the CdO nanoparticle destiny upon their entry into lungs by inhalations, with the main focus on the ultrastructural changes that the nanoparticles may cause to tissues of the primary and secondary target organs. We indeed found the CdO nanoparticles to be transported from the lungs into secondary target organs by blood. In lungs, inhaled CdO nanoparticles caused significant alterations in parenchyma tissue including hyperemia, enlarged pulmonary septa, congested capillaries, alveolar emphysema and small areas of atelectasis. Nanoparticles were observed in the cytoplasm of cells lining bronchioles, in the alveolar spaces as well as inside the membranous pneumocytes and in phagosomes of lung macrophages. Nanoparticles even penetrated through the membrane into some organelles including mitochondria and they also accumulated in the cytoplasmic vesicles. In livers, inhalation caused periportal inflammation and local hepatic necrosis. Only minor changes such as diffusely thickened filtration membrane with intramembranous electron dense deposits were observed in kidney. Taken together, inhaled CdO nanoparticles not only accumulated in lungs but they were also transported to other organs causing serious damage at tissue as well as cellular level.
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http://dx.doi.org/10.3390/ijms17060874DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4926408PMC
June 2016

Wet effluent diffusion denuder: The tool for determination of monoterpenes in forest.

Talanta 2016 06 11;153:260-7. Epub 2016 Mar 11.

Institute of Analytical Chemistry of the CAS, v. v. i., Veveří 97, 60200 Brno, Czech Republic.

Three methods, i.e., the cylindrical wet effluent diffusion denuder (CWEDD)-GCMS, Tenax tubes-GCMS and Proton-Transfer-Reaction Time-of-Flight Mass Spectrometry (PTR-TOF-MS) were compared for the determination of monoterpenes in forest. While the on-line technique (PTR-TOF-MS) allows only for the measurement of sum of monoterpenes, both the off-line preconcentration techniques (CWEDD and Tenax tubes) are suitable for the determination of concentrations of individual monoterpenes due to subsequent analysis of samples by GCMS. The CWEDD-GCMS is the only method that allows sampling of individual monoterpenes with short time intervals of 2-5min. Monoterpenes are absorbed into a liquid (n-heptane), flowing down on the inner wall of the CWEDD, and then the collected liquid with monoterpenes is immediately taken away for the GCMS analysis, which minimizes time when collected monoterpenes are exposed to oxidants presented in the air during sampling. The limits of detection of CWEDD-GCMS are in the range 1-7pptv for individual monoterpenes.
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http://dx.doi.org/10.1016/j.talanta.2016.03.032DOI Listing
June 2016

A portable device for fast analysis of explosives in the environment.

J Chromatogr A 2015 Apr 21;1388:167-73. Epub 2015 Feb 21.

University of Defence, Kounicova 65, 66210 Brno, Czech Republic.

A novel portable device for fast and sensitive analysis of explosives in environmental samples is presented. The developed system consists of miniaturized microcolumn liquid chromatograph, photolytic converter and chemiluminescence detector. The device is able to determine selectively nitramine- and nitroester- and most of nitroaromates-based explosives as well as inorganic nitrates at trace concentrations in water or soil extracts in less than 8 min. The device allows to analyze various environmental samples such as soils or water materials without previous preconcentration. Because of internal power supply, the device ensures 12h of continuous operation. Limits of detection of compounds of interest are in the range of concentrations from 5.0 × 10(-9)M to 8.0 × 10(-5)M for a signal-to-noise ratio of 3. Limits of quantification are in the range of concentrations from 1.7 × 10(-8)M to 2.7 × 10(-4)M for a signal-to-noise ratio of 10. The repeatability of the method (RSD=2.9-5.6%) was determined by repeated injections (n=10) of the standard samples during 4h.
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http://dx.doi.org/10.1016/j.chroma.2015.02.041DOI Listing
April 2015

Embryonic toxicity of nanoparticles.

Cells Tissues Organs 2014 4;199(1):1-23. Epub 2014 Jun 4.

Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Brno, Czech Republic.

Applications of nanoparticles (NP) in medicine, industry and other branches of human activities undoubtedly contribute to technology development and well-being. However, as NP are very small units in a wide range of materials, there is a lack of information related to possible side effects potentially affecting the health of organisms. There is increasing experimental interest in the determination of environmental effects on humans exposed to NP. Most such experimental studies focus on adult populations or adult experimental animals. However, embryos can be more sensitive to pollutants and environmental impacts in some species. Therefore, some investigations dealing particularly with the effects of NP on embryonic development have appeared recently and this issue is becoming of great concern. The aim of this review is to summarize the knowledge on the effects of various nanomaterials on embryonic development. A comprehensive collection of significant experimental nanotoxicity data is presented, which also indicate how the toxic effect of NP can be mediated and modulated with respect to possible effective protection strategies.
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http://dx.doi.org/10.1159/000362163DOI Listing
April 2015

Annular diffusion denuder for simultaneous removal of gaseous organic compounds and air oxidants during sampling of carbonaceous aerosols.

Anal Chim Acta 2012 Feb 3;714:68-75. Epub 2011 Dec 3.

Institute of Analytical Chemistry, Academy of Sciences of the Czech Republic, vvi, Brno, Czech Republic.

A specially designed annular diffusion denuder for simultaneous removal of organic gaseous compounds and atmospheric oxidants in carbonaceous aerosol sampling is presented. Various kinds of denuder coatings were compared with respect to the collection efficiency of both organic gaseous compounds and NO(2) and ozone. The optimum sorbent is a mixture of activated charcoal and sulfite on molecular sieve. To ensure high collection efficiency over long-term field operation, two annular diffusion denuders are combined in series. The first half of the first denuder is filled with Na(2)SO(3) on molecular sieve (23 cm long layer) while the second half of the first denuder and the whole second denuder are filled with activated charcoal (the total length of the charcoal section is 67 cm). At a flow rate of 16.6 L min(-1), the collection efficiency of organic gaseous compounds and atmospheric oxidants in the annular diffusion denuder is better than 95%. Only small losses of aerosol particles (<3.6% in number concentration) were observed in the size range 0.12-2.26 μm. The annular diffusion denuder is compatible with the collection of aerosols on 47-mm diameter quartz fiber filters at a flow rate of 16.6 L min(-1). The use of this denuder enables one to sample carbonaceous aerosols on filters without positive sampling artefacts from volatile organic compounds and interferences from atmospheric oxidants. The annular diffusion denuder has been applied successfully for the sampling of carbonaceous aerosols during field campaigns of typically 1 month each at urban and forested sites in Europe.
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http://dx.doi.org/10.1016/j.aca.2011.11.054DOI Listing
February 2012

Application of wet effluent diffusion denuder for measurement of uptake coefficient of gaseous pollutants.

Talanta 2011 Apr 22;84(2):519-23. Epub 2011 Jan 22.

Department of Organic Chemistry, Faculty of Science, Institute of Molecular and Translational Medicine, Palacký University, 17. listopadu 12, 771 46 Olomouc, Czech Republic.

The comparison of theoretical approaches describing the collection of analyte in the cylindrical wet effluent diffusion denuder (CWEDD) with experimental data is presented. Various absorption liquids were tested for the collection of formaldehyde (distilled-deionized water, H(2)SO(4) solution), acetaldehyde (distilled-deionized water) and nitrous acid (distilled-deionized water, sodium carbonate and sodium bicarbonate solutions of various concentrations and sodium phosphate pH 6-8) in CWEDD. pH of absorption liquids significantly influences the collection of formaldehyde as well as nitrous acid. The collection efficiency of formaldehyde for 0.05 M H(2)SO(4) as absorption liquid was generally higher than for distilled-deionized water. Absorption liquid pH markedly affected the collection efficiency of HONO too (with increasing pH the collection efficiency increase). Data derived by Gormley-Kennedy equation for all investigated compounds were overestimated especially for higher flow rates of air, data calculated with respect to Henry constant are not in good agreement with experimental data and are considerably depended on a determination of the Henry constant value. The CWEDD can be alternative tool for the determination of uptake coefficient. Obtained uptake coefficients were in good agreement with data found in other literature.
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http://dx.doi.org/10.1016/j.talanta.2011.01.032DOI Listing
April 2011

Ozone flux over a Norway spruce forest and correlation with net ecosystem production.

Environ Pollut 2011 May 22;159(5):1024-34. Epub 2010 Dec 22.

Ekotoxa s.r.o.-Centre for Environment and Land Assessment, Otická 37, 746 01 Opava, Czech Republic.

Daily ozone deposition flux to a Norway spruce forest in Czech Republic was measured using the gradient method in July and August 2008. Results were in good agreement with a deposition flux model. The mean daily stomatal uptake of ozone was around 47% of total deposition. Average deposition velocity was 0.39 cm s(-1) and 0.36 cm s(-1) by the gradient method and the deposition model, respectively. Measured and modelled non-stomatal uptake was around 0.2 cm s(-1). In addition, net ecosystem production (NEP) was measured by using Eddy Covariance and correlations with O3 concentrations at 15 m a.g.l., total deposition and stomatal uptake were tested. Total deposition and stomatal uptake of ozone significantly decreased NEP, especially by high intensities of solar radiation.
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http://dx.doi.org/10.1016/j.envpol.2010.11.037DOI Listing
May 2011

Flow-injection chemiluminescence determination of formaldehyde in water.

Talanta 2007 Feb 30;71(2):900-5. Epub 2006 Jun 30.

Institute of Analytical Chemistry, Academy of Sciences of the Czech Republic, Veverí 97, CZ-61142 Brno, Czech Republic.

A modification of the Trautz-Schorigin reaction into a flow-injection analysis configuration is described. Different approaches were used at the optimization of chemiluminescence determination of formaldehyde in water based on the reaction of formaldehyde, gallic acid and hydrogen peroxide in an alkaline solution. Detection system with a 218microl chemiluminescence cell was optimized by both a one-variable-at-a-time method, and a modified simplex method. A calibration graph is linear in the concentration range 4x10(-8) to 1x10(-5)M HCHO. The detection limit of formaldehyde for a signal-to-noise ratio of 3 is 4x10(-8)M. The relative standard deviations for 15 repeated measurements of 1x10(-6) and 5x10(-6)mol l(-1) HCHO are 4.32 and 3.33%, respectively. The analysis time is 1.5min. The method was applied to the determination of formaldehyde in urban rainwater. A comparison of results found by proposed method with those obtained by fluorimetric reference method provided a good agreement.
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http://dx.doi.org/10.1016/j.talanta.2006.05.078DOI Listing
February 2007

Aerosol counterflow two-jets unit for continuous measurement of the soluble fraction of atmospheric aerosols.

Anal Chem 2005 Sep;77(17):5534-41

Institute of Analytical Chemistry, Academy of Sciences of the Czech Republic, Veverí 97, CZ-61142 Brno, Czech Republic.

A new type of aerosol collector employing a liquid at laboratory temperature for continuous sampling of atmospheric particles is described. The collector operates on the principle of a Venturi scrubber. Sampled air flows at high linear velocity through two Venturi nozzles "atomizing" the liquid to form two jets of a polydisperse aerosol of fine droplets situated against each other. Counterflow jets of droplets collide, and within this process, the aerosol particles are captured into dispersed liquid. Under optimum conditions (air flow rate of 5 L/min and water flow rate of 2 mL/min), aerosol particles down to 0.3 microm in diameter are quantitatively collected in the collector into deionized water while the collection efficiency of smaller particles decreases. There is very little loss of fine aerosol within the aerosol counterflow two-jets unit (ACTJU). Coupling of the aerosol collector with an annular diffusion denuder located upstream of the collector ensures an artifact-free sampling of atmospheric aerosols. Operation of the ACTJU in combination with on-line detection devices allows in situ automated analysis of water-soluble aerosol species (e.g., NO2-, NO3-)with high time resolution (as high as 1 s). Under the optimum conditions, the limit of detection for particulate nitrite and nitrate is 28 and 77 ng/m(3), respectively. The instrument is sufficiently rugged for its application at routine monitoring of aerosol composition in the real time.
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http://dx.doi.org/10.1021/ac050343lDOI Listing
September 2005

Wet effluent diffusion denuder technique and the determination of volatile organic compounds in air. II. Monoterpenes.

J Chromatogr A 2002 Oct;973(1-2):211-6

Institute of Analytical Chemistry, Academy of Sciences of the Czech Republic, Brno.

The wet effluent diffusion denuder technique (WEDD), for the determination of alpha- and beta-pinenes, S-limonene, alpha-phellandrene, camphene and delta3-carene in air has been tested. These monoterpenes were continuously preconcentrated into a thin film of methanol (ethanol, 1-propanol and heptane) flowing down the inner wall of the cylindrical wet effluent diffusion denuder. The concentrates were analyzed by GC-FID and GC-MS, respectively.
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http://dx.doi.org/10.1016/s0021-9673(02)01214-1DOI Listing
October 2002