National Repository of Grey Literature 35 records found  previous3 - 12nextend  jump to record: Search took 0.01 seconds. 
Ultrafine particles and their possible role in etiology and development of neurodegenerative diseases
Topinka, Jan ; Závodná, Táňa ; Rössnerová, Andrea ; Rössner ml., Pavel
Air pollutants have been shown to cause a vast amount of different adverse health effects. These effects include impairment of many respiratory (e.g. asthma, chronic obstructive pulmonary disease) and cardiovascular (ischemic heart disease, infarction, stroke) diseases. However, in recent years, the evidence showing effects beyond the lungs and circulatory system are becoming more evident. Neurological diseases, namely Alzheimer's disease (AD) has shown to be associated with living near traffic. However, reason for this has remained unresolved until today. Our new H2020 project TUBE aims on revealing the mechanisms of action of ultrafine particles involved in neurological diseases. The TUBE consortium includes experts in areas of aerosol technology, emission research, engine and fuel research, human clinical studies, epidemiology, emission inventories, inhalation toxicology, neurotoxicology and disease mechanism studies. This enables research of resolving the effects of nanoparticles from different traffic modes for both air quality and concomitant toxic effect of these air pollutants. We will investigate adverse effects of air pollutants using cell cultures, animal exposures and volunteered human exposures as well as the material from epidemiological cohort study. These are going to be compared according to inflammatory, cytotoxic and genotoxic changes and furthermore beyond the current state of the art to neurotoxic and brain health effects. With this approach, we are aiming to a comprehensive understanding of the adverse brain effects of nanoparticles from traffic.
Toxic responses in human lung epithelial cells (BEAS-2B) exposed to particulate matter exhaust emissions from gasoline and biogasoline
Závodná, Táňa ; Líbalová, Helena ; Vrbová, Kristýna ; Sikorová, Jitka ; Vojtíšek-Lom, M. ; Beránek, V. ; Pechout, M. ; Kléma, J. ; Cigánek, M. ; Machala, M. ; Neča, J. ; Rössner ml., Pavel ; Topinka, Jan
Motor vehicle emissions substantially contribute to air pollution worldwide and cause serious health problems. While the deleterious effects of diesel exhaust particulate matter (PM) have been widely studied, much less attention is paid to toxicity of PM emitted by gasoline engines although they also produce considerable amount of PM. The primary objective of this research was to assess toxic potencies of exhaust PM released by conventional gasoline engine fueled with neat gasoline (EU) or gasoline-ethanol blend (15% ethanol, v/v, E15). Despite a similar particle mass (mu g PM/kg fuel) produced by both fuels, PM emitted by E15 contained higher amount of harmful polycyclic aromatic hydrocarbons (PAH) as suggested by chemical analysis. To examine the toxicity of organic PM constituents, human lung BEAS-2B cells were exposed for 4h and 24h to a subtoxic dose of E0 and E15 PM organic extracts. We used genome scale transcriptomic analysis to characterize the toxic response and to identify modulated biological process and pathways. Whereas 4h exposure to both PM extracts resulted in modulation of similar genes and pathways related to lipid and steroid metabolism, activation of PPAR alpha, oxidative stress and immune response, 24h exposure was more specific for each extract, although both induced expression of PAH-metabolic enzymes, modulated metabolism of lipids or activated PPAR alpha, E15 additionally deregulated variety of other pathways. Overall, the PM mass produced by both fuels was similar, however, higher PAH content in E15 PM organic extract may have contributed to more extensive toxic response particularly after 24h exposure in BEAS-2B cells.
Males-females differences in the spectrum of chromosomal aberrations in the group of nanocomposites production workers
Rössnerová, Andrea ; Pelcová, D. ; Ždímal, Vladimír ; Elzeinova, Fatima ; Margaryan, Hasmik ; Chvojková, Irena ; Topinka, Jan ; Schwarz, Jaroslav ; Ondráček, Jakub ; Koštejn, Martin ; Komarc, M. ; Vlčková, Š. ; Fenclová, Z. ; Lischková, L. ; Dvořáčková, Š. ; Rössner ml., Pavel
An increase in the use of nanomaterials (NM) has been witnessed in many areas of human life. Therefore, assessment of genotoxicity of NM and nanoparticles (NP) is one of the main objectives of genetic toxicology. Despite this fact, human cytogenetic studies following the exposure to NP are still rare. Moreover, no relevant information on possible differences in sensitivity to NP related to gender is available.\n\nIn this study we periodically (in September 2016, 2017 and 2018; pre-shift and post-shift each year) analyzed a group of workers (both genders), working long time in nanocomposites research, and matched controls. Aerosol exposure monitoring of particulate matter including nano-sized fractions was carried out during working shift. Micronucleus assay using Human Pan Centromeric probes, was applied to distinguish, besides the frequency of total MN in binucleated cells (BNC), also other types of chromosomal damage (losses and breaks). Moreover, whole-chromosome painting (WCP) for autosome #1 and both gonosomes (X and Y) were applied in third sampling period (2018) with the aim to identify the particular structural and numerical chromosomal aberrations.\n\nObtained results showed: (i) differences in the risk of exposure to NP related to individual working processes (welding, smelting and machining); (ii) differences in chemical composition of nano-fraction; (iii) no effect of chronic exposure of NP (total MN) opposite to significant effect of acute exposure; (iv) gender-related DNA damage differences (females seem to be more sensitive to chromosomal losses). Additional data from WCP suggested increased frequency of numerical aberrations in gonosomes.
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Measurement and toxicity of combustion generated nanoparticles
Sikorová, Jitka ; Topinka, Jan (advisor) ; Klusoň, Petr (referee) ; Bláha, Luděk (referee)
This thesis is focused on nanoparticles produced by internal combustion engines utilized in vehicles. It deals with spatial distribution of nanoparticles within urban areas, impact of alternative fuels usage on particle production and toxicity, and a particle toxicological testing methodology. Monitoring of airborne nanoparticles identified traffic as the main source of airborne nanoparticles in places with heavy traffic load (Prague), as well as in a small city with only local traffic (Čelákovice). Most particles were likely emitted during short episodes of high emissions (e.g. uphill acceleration). During the measurements, high-emission vehicles responsible for a large fraction of the air pollution were also identified. On the other hand, small non-road internal combustion engines, which are not subject to any limit on particle emissions, such as a lawn mower, were operated during the measurement and generated a large number of nanoparticles. The amount and characteristics of the particles produced by combustion depend on the combustion technology and the fuel composition. A large part of the thesis deals with alternative fuels and their effects on the quantity of produced particles and toxicity of organic matter adsorbed on the particles. Hydrotreated vegetable oil (HVO) exhibited the lowest...
Use of transcriptomics to study mechanism of the action of complex mixtures of organic compounds occurring in the ambient air focusing on polycyclic aromatic hydrocarbons
Líbalová, Helena ; Topinka, Jan (advisor) ; Krásný, Libor (referee) ; Postlerová, Pavla (referee)
Polycyclic aromatic hydrocarbons (PAH) represent a large group of organic compounds occuring as pollutants in ambient air. Besides their genotoxic effect, some of them are known to be complete carcinogens and act via nongenotoxic and tumor promoting mechanism. Although effects of many individual compounds are well-documented, human exposure to polycyclic aromatic hydrocarbons in ambient air occurs through complex mixtures and only few studies describe the behavior of PAH in real complex mixtures. The first part of the thesis is dealing with the global gene expression changes in human embryonic lung fibroblasts (HEL) as a consequence of the effect of complex mixtures containing PAH extracted from the respirable airborne particles PM2.5. These particles were collected in 4 localities in the Czech republic (Ostrava - Bartovice, Ostrava - Poruba, Karviná, Třeboň) differing in the level of the air pollution. Gene expression changes induced by three subtoxic concentrations of organic extracts (EOM - extractable organic matter) from each locality after 24 hour incubation were examined by microarray analysis. Pathway analysis using the Kyoto Encyclopedia of Genes and Genomes (KEGG) database was applied to interpret gene expression data. In each locality we identified several deregulated signaling pathways...
Interactions of cells with nanoparticles for bio-medical applications
Bělinová, Tereza ; Hubálek Kalbáčová, Marie (advisor) ; Benson, Veronika (referee) ; Topinka, Jan (referee)
In the past decades, nanoparticles have been viewed as a potentially powerful platform for various applications in biomedical sciences. The possible application of nanoparticles varies from drug delivery agents to novel imaging platforms and surely, some application potential still remains hidden. Thus, it is necessary to broadly study their in vitro behavior in order to assess the precise theranostic potential as well as to distinguish possible threats to human health. Even though nanoparticles are getting more and more attention in current research, still only a limited amount of information is available, especially regarding interactions of ultra-small (< 5 nm) nanoparticles with biological environment and cells. The aim of the work presented herein is to provide the reader with information concerning interactions of various ultra-small nanoparticles (silicon-based, gold, nanodiamonds) with biological environment and human cells. Dose- and time-dependent influence of the various nanoparticles on behavior of different human cells (osteoblasts, monocytes, keratinocytes, mesenchymal stem cells) was established under different conditions, stressing out the importance of protein corona (a layer of proteins originating from cultivation medium attached to nanoparticles). Biocompatibility of two...
Interactions of cells with nanoparticles for bio-medical applications
Bělinová, Tereza ; Hubálek Kalbáčová, Marie (advisor) ; Benson, Veronika (referee) ; Topinka, Jan (referee)
In the past decades, nanoparticles have been viewed as a potentially powerful platform for various applications in biomedical sciences. The possible application of nanoparticles varies from drug delivery agents to novel imaging platforms and surely, some application potential still remains hidden. Thus, it is necessary to broadly study their in vitro behavior in order to assess the precise theranostic potential as well as to distinguish possible threats to human health. Even though nanoparticles are getting more and more attention in current research, still only a limited amount of information is available, especially regarding interactions of ultra-small (< 5 nm) nanoparticles with biological environment and cells. The aim of the work presented herein is to provide the reader with information concerning interactions of various ultra-small nanoparticles (silicon-based, gold, nanodiamonds) with biological environment and human cells. Dose- and time-dependent influence of the various nanoparticles on behavior of different human cells (osteoblasts, monocytes, keratinocytes, mesenchymal stem cells) was established under different conditions, stressing out the importance of protein corona (a layer of proteins originating from cultivation medium attached to nanoparticles). Biocompatibility of two...
Measurement and toxicity of combustion generated nanoparticles
Sikorová, Jitka ; Topinka, Jan (advisor) ; Klusoň, Petr (referee) ; Bláha, Luděk (referee)
This thesis is focused on nanoparticles produced by internal combustion engines utilized in vehicles. It deals with spatial distribution of nanoparticles within urban areas, impact of alternative fuels usage on particle production and toxicity, and a particle toxicological testing methodology. Monitoring of airborne nanoparticles identified traffic as the main source of airborne nanoparticles in places with heavy traffic load (Prague), as well as in a small city with only local traffic (Čelákovice). Most particles were likely emitted during short episodes of high emissions (e.g. uphill acceleration). During the measurements, high-emission vehicles responsible for a large fraction of the air pollution were also identified. On the other hand, small non-road internal combustion engines, which are not subject to any limit on particle emissions, such as a lawn mower, were operated during the measurement and generated a large number of nanoparticles. The amount and characteristics of the particles produced by combustion depend on the combustion technology and the fuel composition. A large part of the thesis deals with alternative fuels and their effects on the quantity of produced particles and toxicity of organic matter adsorbed on the particles. Hydrotreated vegetable oil (HVO) exhibited the lowest...
SIZE AS AN IMPORTANT FACTOR IN NANO-TiO2 TOXICITY IN MACROPHAGE-LIKE CELLS
Líbalová, Helena ; Sikorová, Jitka ; Brzicová, Táňa ; Milcová, Alena ; Vrbová, Kristýna ; Pikal, P. ; Topinka, Jan ; Rössner ml., Pavel
A set of NPs consists of 5 variants of anatase and 5 variants of rutile nanoparticles differing in their diameter (from 3 to 165 nm). TiO2 samples were characterized in the powder form and dispersed in water and cell culture media. Three cytotoxicity assays were used: MTS, WST-1, and LDH. For all nanomaterials, three independent repetitions were carried out. \n\nOverall, cytotoxicity of all NPs was low even at the highest concentration of 256 mu g/ml. The viability of cells did not decrease below 60% for WST-1 and MTS assays and 80% for the LDH assay. Besides concentration, crystalline size was identified as the most important cytotoxic factor. Clear nonlinear relationship between crystalline size and cytotoxicity was detected, higher toxicity induced NPs within the size range 20-60 nm. Increased cytotoxicity in given diameter size range would give an answer to inconsistent findings at size and cytotoxicity relationship.
GENOTOXICITY OF NANOMATERIALS IN BEAS-2B CELLS ANALYZED BY THE IN VITRO MICRONUCLEUS ASSAY
Rössnerová, Andrea ; Červená, Tereza ; Brzicová, Táňa ; Vrbová, Kristýna ; Sikorová, Jitka ; Topinka, Jan ; Rössner ml., Pavel
The tremendous increase of the use of nanomaterials (NMs) has been witnessed during the last decade in many areas of human life including the chemical industry, cosmetics, biomedicine or food technology. The variety of NMs, their unique properties, almost ubiquitous presence and the size range of 1-100 nm raised the interest of toxicologists. The evaluation of the frequency of micronuclei (MN) as a result of the genotoxic events is a broadly utilized and well-established approach in in vitro studies for testing the risk of chemical exposure. Nevertheless, properties of the NMs give rise to the questions concerning the optimal methodological variants of the MN assay. \n\nIn our study, five types of well-characterized NMs (TiO2: NM-101 and NM-103, SiO2: NM-200, Ag: NM-300K and NM-302) of specific size, shape, or e.g. dimensions of aggregates were involved in the genotoxicity testing using four variants of protocols differing in the time of NM exposure, application of cytochalasin-B combined with simultaneous and delayed co-treatment with nanoparticles (NPs). Bronchial epithelial cells (BEAS-2B) were used in this study to fulfil these tasks. Presence of NPs was controlled by transmission electron microscopy (TEM). \n\nObtained results showed the different genotoxic potential of the various TiO2 and Ag NMs (NM-101< NM-103 and NM-300K> NM-302, respectively). Comparison of all testing strategies revealed, that the level of DNA damage can differ based on the time of exposure and the methodological approach. In general, using cytochalasin-B led most frequently to the increase of the genotoxic potential of the tested NMs.

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