46 results on '"Dvořáková M."'
Search Results
2. The impact of the application of compochar on soil moisture, stress, yield and nutritional properties of legumes under drought stress.
- Author
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Soudek P, Langhansová L, Dvořáková M, Revutska A, Petrová Š, Hirnerová A, Bouček J, Trakal L, Hošek P, and Soukupová M
- Subjects
- Droughts, Chlorophyll A, Vegetables, Crops, Agricultural, Pisum sativum, Water, Flavonoids, Soil chemistry, Fabaceae
- Abstract
Nowadays, when climate change is becoming more and more evident, drought stress plays a very important role, including in agriculture. The increasing number of years with extreme temperatures in the Czech Republic has a negative impact on agricultural production, among other things. Therefore, ways are being sought to reduce these negative impacts. One of them may be the use of compochar (a mixture of compost and biochar) to improve water retention in the soil. The effect of compochar addition on soil properties and crop yield was tested under conditions simulating severe drought stress (greenhouse experiments) compared to normal conditions (field experiments). The aim was to find the most suitable ratio of compochar addition that would reduce the negative effects of drought stress on the yield and quality of peas and beans. Tested soil was only able to retain water between 0.03 and 0.18 cm
3 /cm3 , while the compochar itself retained between 0.12 and 0.32 cm3 cm-3 . Three substrate variants were tested by varying the amount of compochar (10, 30 and 50 % v/v) in the soil, and all three substrates showed a similar water content between 0.03 and 0.21 cm3 cm-3 depending on the planted crop and week of cultivation. No apparent stress was observed in crops planted in 100 % compochar. Nevertheless, in general, the trend of chlorophyll a/b ratio increased with increasing amounts of compochar in the soil, indicating stress. Yield increased by approximately 50 % for both test crops when 30 % compochar was used as substrate. The flavonoid content in beans was between 410 and 500 μg CE g-1 DW and in peas was approximately 300 μg CE g-1 DW. The results showed that the utilization of compochar had no effect on either total phenol content, flavonoid content or antioxidant capacity. The combination of compochar with soil (30 %) was found to positively affect the (i) soil moisture, (ii) crop yield, and (iii) nutritional properties of peas and beans and (iv) the ability of plants to withstand drought stress., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)- Published
- 2024
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3. The Potential for Genotoxicity, Mutagenicity and Endocrine Disruption in Triclosan and Triclocarban Assessed through a Combination of In Vitro Methods.
- Author
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Chrz J, Dvořáková M, Kejlová K, Očadlíková D, Svobodová L, Malina L, Hošíková B, Jírová D, Bendová H, and Kolářová H
- Abstract
Triclosan and Triclocarban, preservatives widely used in cosmetics and other consumer products, underwent evaluation using a battery of new-approach methodologies in vitro (NAMs). Specifically, the Microplate Ames Test (MPF™ Test, Xenometrix, Allschwil, Switzerland) was employed to assess mutagenicity, the Comet assay in vitro on the HaCat cell line and the Mammalian Chromosome Aberration Test were utilized to evaluate genotoxicity, and the XenoScreen
® YES/YAS assay was applied to investigate endocrine disruption. The chemicals did not exhibit any positive responses for mutagenicity. However, the mammalian chromosome aberration test identified both chemicals as being positive for genotoxicity at 10 µg/mL. In the Comet assay, the percentage of DNA in the tail significantly increased in a concentration-dependent manner (at 5 and 10 µg/mL for Triclosan, at 2.5, 5, and 10 µg/mL for Triclocarban). The positive response depended on the increasing concentration and the duration of exposure. Triclosan, but not Triclocarban in any of the endocrine assays performed, indicated a potential for endocrine activity in the anti-estrogenic and anti-androgenic assays. The positive in vitro results detected were obtained for concentrations relevant to final products. The alarming findings obtained with the use of new-approach methodologies (NAMs) justify the current precautionary regulatory approach, limiting the use of these preservatives.- Published
- 2023
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4. Biological analyses of the effects of TiO2 and PEG-b-PLA nanoparticles on three-dimensional spheroid-based tumor.
- Author
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Koňáriková K, Girašková GM, Žitňanová I, Dvořáková M, Rollerová E, Scsuková S, Bizik J, Janubová M, and Muchová J
- Subjects
- Humans, Polyethylene Glycols pharmacology, Cell Line, Tumor, Polyesters, Antineoplastic Agents pharmacology, Nanoparticles
- Abstract
The aim of our study was to monitor the antiproliferative/ cytotoxic and genotoxic effects of both, poly(ethylene glycol)-block-poly(lactic acid) (PEG-b-PLA) and titanium dioxide (TiO2) nanoparticles on the tumor (HT-29, MCF-7, U118MG) and healthy (HEK-293T) cell lines during 2D cultivation and during cultivation in the spheroid form (3D cultivation). Cells or spheroids were cultivated with nanoparticles (0.01, 0.1, 1, 10, 50, and 100 ?g/ml) for 72 hours. The cytotoxic effect was determined by the MTT test and the genotoxic effect by the comet assay. We found that 2D cultivation of tumor cell lines with PEG-b-PLA and TiO2 nanoparticles had an anti-proliferative effect on human colon cancer cell line HT-29, human breast cancer cell line MCF-7, human glioma cell line U-118MG during 72h cultivation, but not on control/healthy HEK-293T cells. At the concentrations used, the tested nanoparticles caused no cytotoxic effect on tumor cell lines. Nanoparticles PEG-b-PLA induced significant damage to DNA in HT-29 and MCF-7 cells, while TiO2 nanoparticles in MCF-7 and U-118MG cells. Only PEG-b-PLA nanoparticles caused cytotoxic (IC50 = 7 mikrog/ml) and genotoxic effects on the healthy cell line HEK-293T after 72h cultivation. The cells which were cultivated in spheroid forms were more sensitive to both types of nanoparticles. After 72h cultivation, we observed the cytotoxic effect on both, the tumor and healthy cell lines.
- Published
- 2023
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5. The Safety Assessment of Cosmetic Perfumes by Using In Chemico and In Vitro Methods in Combination with GC-MS/MS Analysis.
- Author
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Dvořáková M, Svobodová L, Rucki M, Ševčík V, Hošíková B, Chrz J, Bendová H, Kejlová K, Očadlíková D, Malý M, Kolářová H, Mannerström M, Kanďárová H, and Jírová D
- Subjects
- Animals, Humans, Tandem Mass Spectrometry, Gas Chromatography-Mass Spectrometry, Pilot Projects, Allergens toxicity, Allergens analysis, Perfume analysis, Tea Tree Oil, Cosmetics toxicity
- Abstract
Animal testing has been prohibited for the safety assessment of cosmetic ingredients or finished products. Thus, alternative non-animal methods, followed by confirmatory clinical studies on human volunteers, should be used as the sole legally acceptable approach within the EU. The safety assessment of cosmetic products requires the involvement of multiple scientific disciplines, including analytical chemistry and biomedicine, as well as in chemico , in vitro and in silico toxicology. Recent data suggest that fragrance components may exert multiple adverse biological effects, e.g. cytotoxicity, skin sensitisation, (photo)genotoxicity, mutagenicity, reprotoxicity and endocrine disruption. Therefore, a pilot study was conducted with selected samples of fragrance-based products, such as deodorant, eau de toilette and eau de parfum, with the aim of integrating results from a number of alternative non-animal methods suitable for the detection of the following toxicological endpoints: cytotoxicity (with 3T3 Balb/c fibroblasts); skin sensitisation potential ( in chemico method, DPRA); skin sensitisation potential (LuSens in vitro method, based on human keratinocytes); genotoxicity potential ( in vitro Comet assay with 3T3 Balb/c cells); and endocrine disruption ( in vitro YES/YAS assay). The presence of twenty-four specific known allergens in the products was determined by using GC-MS/MS. The strategies for estimation of the NOAEL of a mixture of allergens, which were proposed by the Scientific Committee on Consumer Products in their 'Opinion on Tea tree oil' document and by the Norwegian Food Safety Authority in their 'Risk Profile of Tea tree oil' report, were used as models for the NOAEL estimation of the mixtures of allergens that were identified in the individual samples tested in this study.
- Published
- 2023
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6. Hydrothermal deposition as a novel method for the preparation of Co-Mn mixed oxide catalysts supported on stainless steel meshes: application to VOC oxidation.
- Author
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Topka P, Jirátová K, Dvořáková M, Balabánová J, Koštejn M, and Kovanda F
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- Catalysis, Oxidation-Reduction, Stainless Steel, Oxides, Volatile Organic Compounds
- Abstract
The aim of this work was to develop a novel method for the preparation of structured Co-Mn mixed oxide catalysts: deposition on stainless steel meshes by hydrothermal synthesis. The use of meshes enabled the deposition of a thin layer of the active phase, which significantly suppressed the influence of internal diffusion. Consequently, the prepared catalysts exhibited from 48 to 114 times higher catalytic activity in ethanol oxidation than the commercial pelleted Co-Mn-Al catalyst. Moreover, we have shown that their catalytic activity correlated with the proportion of surface oxygen vacancies determined by XPS. Finally, the outstanding activity of the catalyst with Co:Mn ratio of 0.5 was ascribed to the mutual effect of high number of oxygen vacancies and exceptional redox properties., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
- Published
- 2022
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7. The hCOMET project: International database comparison of results with the comet assay in human biomonitoring. Baseline frequency of DNA damage and effect of main confounders.
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Milić M, Ceppi M, Bruzzone M, Azqueta A, Brunborg G, Godschalk R, Koppen G, Langie S, Møller P, Teixeira JP, Alija A, Anderson D, Andrade V, Andreoli C, Asllani F, Bangkoglu EE, Barančoková M, Basaran N, Boutet-Robinet E, Buschini A, Cavallo D, Costa Pereira C, Costa C, Costa S, Da Silva J, Del Boˊ C, Dimitrijević Srećković V, Djelić N, Dobrzyńska M, Duračková Z, Dvořáková M, Gajski G, Galati S, García Lima O, Giovannelli L, Goroshinskaya IA, Grindel A, Gutzkow KB, Hernández A, Hernández C, Holven KB, Ibero-Baraibar I, Ottestad I, Kadioglu E, Kažimirová A, Kuznetsova E, Ladeira C, Laffon B, Lamonaca P, Lebailly P, Louro H, Mandina Cardoso T, Marcon F, Marcos R, Moretti M, Moretti S, Najafzadeh M, Nemeth Z, Neri M, Novotna B, Orlow I, Paduchova Z, Pastor S, Perdry H, Spremo-Potparević B, Ramadhani D, Riso P, Rohr P, Rojas E, Rossner P, Safar A, Sardas S, Silva MJ, Sirota N, Smolkova B, Staruchova M, Stetina R, Stopper H, Surikova EI, Ulven SM, Ursini CL, Valdiglesias V, Valverde M, Vodicka P, Volkovova K, Wagner KH, Živković L, Dušinská M, Collins AR, and Bonassi S
- Subjects
- Biomarkers blood, DNA Damage genetics, DNA Damage physiology, Humans, Comet Assay methods
- Abstract
The alkaline comet assay, or single cell gel electrophoresis, is one of the most popular methods for assessing DNA damage in human population. One of the open issues concerning this assay is the identification of those factors that can explain the large inter-individual and inter-laboratory variation. International collaborative initiatives such as the hCOMET project - a COST Action launched in 2016 - represent a valuable tool to meet this challenge. The aims of hCOMET were to establish reference values for the level of DNA damage in humans, to investigate the effect of host factors, lifestyle and exposure to genotoxic agents, and to compare different sources of assay variability. A database of 19,320 subjects was generated, pooling data from 105 studies run by 44 laboratories in 26 countries between 1999 and 2019. A mixed random effect log-linear model, in parallel with a classic meta-analysis, was applied to take into account the extensive heterogeneity of data, due to descriptor, specimen and protocol variability. As a result of this analysis interquartile intervals of DNA strand breaks (which includes alkali-labile sites) were reported for tail intensity, tail length, and tail moment (comet assay descriptors). A small variation by age was reported in some datasets, suggesting higher DNA damage in oldest age-classes, while no effect could be shown for sex or smoking habit, although the lack of data on heavy smokers has still to be considered. Finally, highly significant differences in DNA damage were found for most exposures investigated in specific studies. In conclusion, these data, which confirm that DNA damage measured by the comet assay is an excellent biomarker of exposure in several conditions, may contribute to improving the quality of study design and to the standardization of results of the comet assay in human populations., Competing Interests: Declaration of Competing Interest The authors report no declarations of interest., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)
- Published
- 2021
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8. Comparison of methods used for evaluation of mutagenicity/genotoxicity of model chemicals - parabens.
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Chrz J, Hošíková B, Svobodová L, Očadlíková D, Kolářová H, Dvořáková M, Kejlová K, Malina L, Jírová G, Vlková A, and Mannerström M
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- Animals, Cell Survival drug effects, Comet Assay, HaCaT Cells, Humans, Lymphocytes pathology, Micronuclei, Chromosome-Defective chemically induced, Micronucleus Tests, Risk Assessment, Animal Testing Alternatives, Chromosome Aberrations chemically induced, DNA Damage, Lymphocytes drug effects, Mutagenesis drug effects, Mutagenicity Tests, Parabens toxicity
- Abstract
Growing worldwide efforts to replace (reduce) animal testing and to improve alternative in vitro tests which may be more efficient in terms of both time, cost and scientific validity include also genotoxicity/mutagenicity endpoints. The aim of the review article was to summarize currently available in vitro testing approaches in this field, their regulatory acceptance and recommended combinations for classification of chemicals. A study using the combination of Comet Assay performed on two cell lines and the Chromosomal Aberration test on human peripheral lymphocytes was performed with the aim to predict the genotoxic potential of selected paraben esters, serving as a model chemical group. Parabens are widely used in consumer products as preservatives and have been reported to exhibit inconclusive results in numerous genotoxicity studies. The Comet Assay identified Ethylparaben and Benzylparaben as potentially genotoxic. The Chromosomal Aberration test revealed weak genotoxic potential in case of Ethylparaben and positive genotoxicity in case of Butylparaben, Propylparaben and Isopropylparaben. The main reasons for variability seem to be limited water solubility of parabens, determining their bioavailability at the cellular level, and absence of metabolic activation in the Comet Assay. The results confirmed that the Comet Assay should serve as a screening test and should not be used as a stand-alone method for classification of genotoxicity. The weight of evidence approach in risk assessment should be supported with data generated with the use of human relevant in vitro methods based on cells / tissues of human origin.
- Published
- 2020
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9. Iodine, thyroglobulin and thyroid gland.
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Bílek R, Dvořáková M, Grimmichová T, and Jiskra J
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- Animals, Humans, Iodine adverse effects, Thyroid Diseases metabolism, Thyroid Diseases pathology, Thyroid Gland metabolism, Thyroid Gland pathology, Iodine administration & dosage, Thyroglobulin metabolism, Thyroid Diseases chemically induced, Thyroid Gland drug effects
- Abstract
Iodine is essential in the biosynthesis of thyroid hormones that affect metabolic processes in the organism from the prenatal state to the elderly. The immediate indicator of iodine intake is the concentration of iodine in urine, but the indicator of iodine intake in the longer term of several months is thyroglobulin (Tg). Tg negatively correlated with increasing intake of iodine in population that do not suffer from thyroid disease, while a more than adequate to excessive iodine intake leads to an increase in Tg. The dependence of Tg on iodine can be described by a U-shaped curve. Thyroglobulin in serum is elevated in thyroid disease mainly in hyperthyroidism (diagnosis E05 of WHO ICD-10 codes) and in goiter (diagnosis E04 of WHO ICD-10 codes). Tg values decrease below 20 microg/l after effective treatment of patients with thyroid disease. Thyroglobulin may thus be an indicator of thyroid stabilization and the success of the thyroid gland treatment.
- Published
- 2020
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10. Familial hypocalciuric hypercalcemia in an index male: grey zones of the differential diagnosis from primary hyperparathyroidism in a 13-year clinical follow up.
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Zajíčková K, Dvořáková M, Moravcová J, Včelák J, and Goltzman D
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- Adult, Calcium blood, Diagnosis, Differential, Follow-Up Studies, Humans, Hypercalcemia blood, Hypercalcemia diagnosis, Hypercalcemia diagnostic imaging, Hyperparathyroidism, Primary blood, Hyperparathyroidism, Primary diagnostic imaging, Male, Positron Emission Tomography Computed Tomography methods, Prognosis, Receptors, Calcium-Sensing blood, Vitamin D blood, Hypercalcemia congenital, Hyperparathyroidism, Primary diagnosis
- Abstract
Familial hypocalciuric hypercalcemia (FHH) type 1, caused by a heterozygous inactivating mutation of the gene encoding the calcium-sensing receptor (CaSR), is characterized by mild to moderate hypercalcemia, hypocalciuria and inappropriately normal or elevated parathyroid hormone (PTH). FHH must be differentiated from primary hyperparathyroidism (PHPT) because parathyroidectomy is ineffective in the former. Herein, we report a 39-year-old male patient with a 13-year history of asymptomatic PTH-dependent hypercalcemia (mean calcium of 2.88 mmol/l; reference range 2.15-2.55 mmol/l) and calcium-to-creatinine clearance ratio (Ca/Cr) ranging from 0.007 to 0.0198, which is consistent with either FHH or PHPT. Although a family history of hypercalcemia was negative, and PET-CT with fluorocholine was suggestive of a parathyroid adenoma, genetic analysis of the CaSR gene identified a heterozygous inactivating mutation NM_000388.4:c.1670G>A p. (Gly557Glu) in exon 6 and a polymorphism NM_000388.4:c.1192G>A p. (Asp398Asn) in exon 4. The G557E mutation has been previously reported in a Japanese family in which all family members with the mutation had Ca/Cr below 0.01 consistent with FHH. The biochemical profile of FHH and PHPT may overlap. Our FHH patient with a G557E CaSR mutation illustrates that the differential diagnosis can be difficult in an index case with no family history, (false) positive parathyroid imaging and higher calciuria than expected for FHH. Calcium intake, vitamin D status and bone resorption might have contributed to the Ca/Cr variations over a 13-year clinical follow up. This case thus emphasizes the irreplaceable role of genetic testing of the CaSR gene when clinical evaluation is inconclusive.
- Published
- 2020
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11. Toxicological testing of a photoactive phthalocyanine-based antimicrobial substance.
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Kejlová K, Bendová H, Chrz J, Dvořáková M, Svobodová L, Vlková A, Kubáč L, Kořínková R, Černý J, Očadlíková D, Rucki M, Heinonen T, Jírová D, Letašiová S, Kandarova H, and Kolářová H
- Subjects
- Animals, Anti-Infective Agents pharmacokinetics, Cells, Cultured, Chick Embryo, Chorioallantoic Membrane blood supply, Chorioallantoic Membrane drug effects, DNA Damage, Estrogen Receptor alpha metabolism, Eye drug effects, Humans, Indoles pharmacokinetics, Irritants pharmacokinetics, Isoindoles, Lymphocytes drug effects, Mice, Inbred BALB C, Photochemical Processes, Receptors, Androgen metabolism, Skin drug effects, Skin metabolism, Skin Absorption, Swine, Toxicity Tests, Anti-Infective Agents toxicity, Indoles toxicity, Irritants toxicity
- Abstract
The aim of the study was toxicological testing of an innovative and efficient antimicrobial agent based on photoactive phthalocyanine (Pc) derivative. A promising Aluminium phthalocyanine (AlPc) with efficient and stable antimicrobial effects was subjected to a battery of toxicological tests to avoid local and systemic toxicity hazard. In compliance with the current European legislation restricting the use of experimental animals, the methods comprised exclusively in vitro procedures based on cellular and tissue models of human origin or mimicking human tissues. The battery of toxicological tests to identify local toxicity included skin corrosion/irritation, eye irritation, and phototoxicity. The basic systemic toxicity tests included acute toxicity, skin sensitization, genotoxicity, and endocrine disruption. The results showed that AlPc induced skin and eye irritation, exhibited borderline sensitization potential and mutagenic potential in one test strain of the Ames test, which was not confirmed in the chromosome aberration test. The AlPc was found to be phototoxic. The results from the cytotoxicity test designed for acute oral toxicity estimation were not conclusive, the acute toxicity potential has to be determined by conventional tests in vivo. Regarding endocrine disruption, no agonistic activity of the AlPc on human estrogen receptor α, nor human androgen receptor was observed. The skin penetration/absorption test revealed that the AlPc has not penetrated into the dermis and receptor fluid, confirming no risk of systemic exposure via the bloodstream., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests., (Copyright © 2020 Elsevier Inc. All rights reserved.)
- Published
- 2020
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12. Structured cobalt oxide catalysts for VOC abatement: the effect of preparation method.
- Author
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Topka P, Dvořáková M, Kšírová P, Perekrestov R, Čada M, Balabánová J, Koštejn M, Jirátová K, and Kovanda F
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- Catalysis, Cobalt, Oxides, Volatile Organic Compounds
- Abstract
Magnetron sputtering was employed for the deposition of cobalt oxide thin films on stainless steel meshes. Catalysts prepared by sputtering in inert and oxidation atmosphere were compared with those obtained by electrochemical deposition and hydrothermal synthesis. Systematic characterization using X-ray diffraction, scanning electron microscopy, N
2 physisorption, infrared spectroscopy, Raman spectroscopy, and temperature-programmed reduction by hydrogen allowed detailed monitoring of their physicochemical properties. Ethanol gas-phase oxidation was employed as a model reaction to reveal the catalytic performance of the catalysts. It was shown that the catalyst prepared by magnetron sputtering in oxidation atmosphere exhibited the best mechanical stability among all studied catalysts. Moreover, its catalytic activity was 18 times higher than that of pelletized commercial cobalt oxide.- Published
- 2020
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13. Easy and Inexpensive Method for Multiclass Analysis of 41 Food Contact Related Contaminants in Fatty Food by Liquid Chromatography-Tandem Mass Spectrometry.
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Vavrouš A, Ševčík V, Dvořáková M, Čabala R, Moulisová A, and Vrbík K
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- Benzhydryl Compounds analysis, Phenols analysis, Phthalic Acids analysis, Chromatography, High Pressure Liquid methods, Food Analysis methods, Food Contamination analysis, Tandem Mass Spectrometry methods
- Abstract
Food contact materials (FCMs) may release their chemical components into food and thus raise safety concerns. This paper attempted to study the presence of four major groups of FCM-related endocrine disruptors in fatty food: dialkyl phthalates, bisphenols, printing ink photoinitiators, and polyfluoroalkyl substances. All 41 target compounds were analyzed simultaneously by means of liquid chromatography coupled to tandem mass spectrometry. The sample preparation was significantly streamlined to reduce analysis costs by employing acetonitrile extraction, extract modification by water, and refrigeration at 5 °C. The new method was validated and applied to 60 real samples, including edible oils, butter, and chocolate, where 16 target compounds were measured at levels ≤13000 ng/g. The study also described the blank level increase and sensitivity loss caused by impurities present in the HPLC methanol solvent.
- Published
- 2019
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14. Toxicity of food contact paper evaluated by combined biological and chemical methods.
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Kejlová K, Dvořáková M, Vavrouš A, Ševčík V, Kanďárová H, Letašiová S, Sosnovcová J, and Jírová D
- Subjects
- Animals, BALB 3T3 Cells, Biological Assay, Cell Survival drug effects, Cytokines metabolism, Food Contamination, Humans, Intestinal Absorption, Intestinal Mucosa drug effects, Intestinal Mucosa metabolism, Mice, Phthalic Acids analysis, Phthalic Acids toxicity, Polycyclic Aromatic Hydrocarbons analysis, Polycyclic Aromatic Hydrocarbons toxicity, Receptors, Androgen genetics, Receptors, Androgen metabolism, Receptors, Estrogen genetics, Receptors, Estrogen metabolism, Risk Assessment, Saccharomyces cerevisiae genetics, Food Packaging, Paper
- Abstract
The study was focused on assessment of potential health risks of paper-based food contact materials (FCMs) in a step-wise approach using three toxicological bioassays in vitro and chemical analyses of migrating contaminants. 3T3 NRU cytotoxicity test showed high sensitivity to detect basal toxicity of FCMs extracts and served as a first-line test for selection of samples for further testing. The reconstructed human intestine model EpiIntestinal showed more realistic tissue response than cell culture monolayer and higher resistance despite prolonged exposure to the selected 6 samples, i.e. negligible decrease of viability and intestinal penetration, nevertheless an increase of IL-8 after exposure to black printed sample extract. Yeast based assays identified weak agonistic/antagonostic activity to human androgen receptor of the black printed sample. In accordance with the biological effects, the targeted LC and GC analytical methods confirmed the presence of high amounts of phthalates, photoinitiators and PAHs that could justify the hazard of the black printed sample. Heavily printed uncoated FCMs are recognized not to be suitable for direct contact with food. The selected bioassays and chemical analyses might be useful tools to detect targeted biological effects of xenobiotics suspected to contribute to human exposure from food., (Copyright © 2019 Elsevier Ltd. All rights reserved.)
- Published
- 2019
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15. Role of oxidative stress, adiponectin and endoglin in the pathophysiology of erectile dysfunction in diabetic and non-diabetic men.
- Author
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Trebatický B, Žitňanová I, Dvořáková M, Országhová Z, Paduchová Z, Ďuračková Z, Breza J, and Muchová J
- Subjects
- Adult, Diabetes Mellitus, Type 2 diagnosis, Diabetes Mellitus, Type 2 epidemiology, Erectile Dysfunction diagnosis, Erectile Dysfunction epidemiology, Humans, Male, Middle Aged, Adiponectin blood, Diabetes Mellitus, Type 2 blood, Endoglin blood, Erectile Dysfunction blood, Oxidative Stress physiology
- Abstract
Erectile dysfunction (ED) and diabetes mellitus (DM) share common pathophysiological risk factors including endothelial dysfunction which together with hyperglycemia contribute to the increased oxidative/glycooxidative stress. A reduced NO concentration is insufficient for relaxation processes in the penis. Chronic inflammation and endoglin are involved in the regulation of endothelial function. Adiponectin from the adipose tissue has anti-inflammatory effects. Our study aimed to investigate the relation between erectile function in patients with and without DM and the oxidative stress, hormone adiponectin, and endothelial dysfunction marker endoglin. Men (n=32) with ED evaluated by the International Index of Erectile function (IIEF-5) questionnaire (17 without DM (NDM); 15 with type 2 diabetes mellitus (DM)) and 31 controls were included. Advanced glycation end products (AGEs), 8-isoprostanes (8-isoP), protein carbonyls, antioxidant capacity, adiponectin and endoglin were determined in the blood. DM patients compared to NDM patients and controls, had increased levels of glucose, C-reactive protein, triacylglycerols, 8-isoP, AGEs, endoglin and BMI. IIEF-5 score, NO and adiponectin levels were decreased. We are the first to find out that endoglin shows a negative correlation with erectile function in NDM, but not in DM patients. Endoglin can be considered as endothelial dysfunction marker in nondiabetic men suffering from ED.
- Published
- 2019
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16. Genes and Mechanisms Responsible for Expansion of Acute Myeloid Leukaemia Blasts.
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Dvořák M and Dvořáková M
- Subjects
- Bone Marrow metabolism, Chromosome Aberrations, Humans, Leukemia, Myeloid, Acute genetics, Mutation genetics, Phenotype, Leukemia, Myeloid, Acute metabolism
- Abstract
Acute myeloid leukaemia (AML) is the leading form of fatal acute leukaemia in adults. AML is a heterogeneous disease with respect to responsible mutations and chromosomal abnormalities as well as to their clinicopathological image. In recent years, great progress has been made in techniques allowing detection of genetic changes in both de novo AML and in secondary AML induced by other haematological disorders or therapy, and in detection of residual disease after therapy. Accumulated knowledge allowed better understanding of the molecules and mechanisms involved not only in the formation and expansion of a primary leukaemia-founding clone, but also of a temporal order of changes leading to the fully malignant phenotype. The recent knowledge of bone marrow (BM) compartments and interrelations among various BM resident and recruited cell types helps in understanding the AML development. The progress in the techniques and knowledge will result in the development and use of molecularly targeted therapies tailored to individual patient needs.
- Published
- 2019
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17. Anti-apoptotic properties of carbon monoxide in porcine oocyte during in vitro aging.
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Němeček D, Dvořáková M, Heroutová I, Chmelíková E, and Sedmíková M
- Abstract
If fertilization of matured oocyte does not occur, unfertilized oocyte undergoes aging, resulting in a time-dependent reduction of the oocyte's quality. The aging of porcine oocytes can lead to apoptosis. Carbon monoxide (CO), a signal molecule produced by the heme oxygenase (HO), possesses cytoprotective and anti-apoptotic effects that have been described in somatic cells. However, the effects of CO in oocytes have yet to be investigated. By immunocytochemistry method we detected that both isoforms of heme oxygenase (HO-1 and HO-2) are present in the porcine oocytes. Based on the morphological signs of oocyte aging, it was found that the inhibition of both HO isoforms by Zn-protoporphyrin IX (Zn-PP IX) leads to an increase in the number of apoptotic oocytes and decrease in the number of intact oocytes during aging. Contrarily, the presence of CO donors (CORM-2 or CORM-A1) significantly decrease the number of apoptotic oocytes while increasing the number of intact oocytes. We also determined that CO donors significantly decrease the caspase-3 (CAS-3) activity. Our results suggest that HO/CO contributes to the sustaining viability through regulation of apoptosis during in vitro aging of porcine oocytes., Competing Interests: The authors declare there are no competing interests.
- Published
- 2017
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18. Behaviour of silver nanoparticles in simulated saliva and gastrointestinal fluids.
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Pinďáková L, Kašpárková V, Kejlová K, Dvořáková M, Krsek D, Jírová D, and Kašparová L
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- Humans, Particle Size, Pilot Projects, Tissue Culture Techniques, Gastric Juice chemistry, Metal Nanoparticles chemistry, Saliva chemistry, Silver
- Abstract
Continuously increasing application of silver nanoparticles (AgNPs) requires information on their safety and performance under biological conditions. Assessment of AgNPs in biological systems is also related to availability of robust toxicological methods for evaluation of toxic potential of AgNPs and information on their physicochemical state. Silver nanoparticles were subjected to action of simulated saliva, gastric and intestinal fluids, appropriately supplemented with digestive enzymes pepsin or pancreatin. The behaviour of AgNPs was determined using dynamic light scattering and transmission electron microscopy, and their toxicity as well as capability to induce inflammatory reactions were assessed using reconstructed human tissue models (EpiOral, EpiGingival, EpiIntestinal). The study revealed that during exposure to the fluids, AgNPs size and morphology changed and depended on composition and pH of the respective fluid. If present, the change in terms of growth of AgNPs size occurred immediately after contact of AgNPs with the respective fluid and continued with prolonged time of contact. A pilot study on reconstituted human tissue models revealed low toxicity and inflammatory effects of AgNPs and confirmed the suitability of 3-D models for toxicological studies including bioavailability., (Copyright © 2017 Elsevier B.V. All rights reserved.)
- Published
- 2017
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19. Basal Cell Carcinoma With Matrical Differentiation: Clinicopathologic, Immunohistochemical, and Molecular Biological Study of 22 Cases.
- Author
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Kyrpychova L, Carr RA, Martinek P, Vanecek T, Perret R, Chottová-Dvořáková M, Zamecnik M, Hadravsky L, Michal M, and Kazakov DV
- Subjects
- Adult, Aged, Aged, 80 and over, Biomarkers, Tumor genetics, Biomarkers, Tumor metabolism, Carcinoma, Basal Cell genetics, Carcinoma, Basal Cell metabolism, Carcinoma, Basal Cell mortality, Cell Differentiation, Female, Follow-Up Studies, Hair Diseases genetics, Hair Diseases metabolism, Hair Diseases mortality, High-Throughput Nucleotide Sequencing, Humans, Immunohistochemistry, Male, Middle Aged, Mutation, Pilomatrixoma genetics, Pilomatrixoma metabolism, Pilomatrixoma mortality, Prognosis, Skin Neoplasms genetics, Skin Neoplasms metabolism, Skin Neoplasms mortality, Carcinoma, Basal Cell pathology, Hair Diseases pathology, Pilomatrixoma pathology, Skin Neoplasms pathology
- Abstract
Basal cell carcinoma (BCC) with matrical differentiation is a fairly rare neoplasm, with about 30 cases documented mainly as isolated case reports. We studied a series of this neoplasm, including cases with an atypical matrical component, a hitherto unreported feature. Lesions coded as BCC with matrical differentiation were reviewed; 22 cases were included. Immunohistochemical studies were performed using antibodies against BerEp4, β-catenin, and epithelial membrane antigen (EMA). Molecular genetic studies using Ion AmpliSeq Cancer Hotspot Panel v2 by massively parallel sequencing on Ion Torrent PGM were performed in 2 cases with an atypical matrical component (1 was previously subjected to microdissection to sample the matrical and BCC areas separately). There were 13 male and 9 female patients, ranging in age from 41 to 89 years. Microscopically, all lesions manifested at least 2 components, a BCC area (follicular germinative differentiation) and areas with matrical differentiation. A BCC component dominated in 14 cases, whereas a matrical component dominated in 4 cases. Matrical differentiation was recognized as matrical/supramatrical cells (n=21), shadow cells (n=21), bright red trichohyaline granules (n=18), and blue-gray corneocytes (n=18). In 2 cases, matrical areas manifested cytologic atypia, and a third case exhibited an infiltrative growth pattern, with the tumor metastasizing to a lymph node. BerEP4 labeled the follicular germinative cells, whereas it was markedly reduced or negative in matrical areas. The reverse pattern was seen with β-catenin. EMA was negative in BCC areas but stained a proportion of matrical/supramatrical cells. Genetic studies revealed mutations of the following genes: CTNNB1, KIT, CDKN2A, TP53, SMAD4, ERBB4, and PTCH1, with some differences between the matrical and BCC components. It is concluded that matrical differentiation in BCC in most cases occurs as multiple foci. Rare neoplasms manifest atypia in the matrical areas. Immunohistochemical analysis for BerEP4, EMA, and β-catenin can be helpful in limited biopsy specimens. From a molecular biological prospective, BCC and matrical components appear to share some of the gene mutations but have differences in others, but this observation must be validated in a large series.
- Published
- 2017
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20. Heme oxygenase/carbon monoxide in the female reproductive system: an overlooked signalling pathway.
- Author
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Němeček D, Dvořáková M, and Sedmíková M
- Abstract
For a long time, carbon monoxide (CO) was known for its toxic effect on organisms. But there are still many things left to discover on that molecule. CO is formed directly in the body by the enzymatic activity of heme oxygenase (HO). CO plays an important role in many physiological processes, such as cell protections (against various stress factors), and the regulation of metabolic processes. Recent research proves that CO also operates in the female reproductive system. At the centre of interest is the importance of CO for gestation. During the gestation period, CO is an important element affecting the proper function of the feto-placental unit and generally affects fetal survivability rates. Gestation is one of the most important processes of successful reproduction, although there are more relevant processes that need to be researched. While already proven that CO influences steroidogenesis and the corpus luteum survivability rate, our knowledge concerning the function and importance of CO in the reproductive system is still relatively limited. As an example, our knowledge of CO function in an oocyte, the most important cell for reproduction, is almost non-existent. The aim of this review is to summarize our current knowledge concerning the function of CO in the female reproductive system.
- Published
- 2017
21. Effect of Neonatal Exposure to Poly(Ethylene Glycol)- block -Poly(Lactic Acid) Nanoparticles on Oxidative State in Infantile and Adult Female Rats.
- Author
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Dvořáková M, Rollerová E, Scsuková S, Bujňáková Mlynarčíková A, Laubertová L, and Žitňanová I
- Subjects
- Animals, Female, Nanoparticles analysis, Rats, Rats, Wistar, Lactates metabolism, Nanoparticles metabolism, Oxidative Stress drug effects, Polyethylene Glycols metabolism
- Abstract
Our goal was to evaluate the potential health risk of the polymeric NP, poly(ethylene glycol)- block -poly(lactic acid) (PEG- b -PLA), from the view of redox imbalance of the organism in two different life stages. Female Wistar rats were neonatally administered intraperitoneally with PEG- b -PLA NPs [20 mg/kg of b.w. (PEG20) or 40 (PEG40) mg/kg of b.w.] from postnatal day 4 (PND4) to PND7. We measured antioxidant capacity (TEAC), level of protein carbonyls and lipoperoxides in plasma, activities of catalase, glutathione peroxidase (GPx), and superoxide dismutase (SOD) in hemolysates of infantile (sacrificed on PND17) and adult (sacrificed after PND176) rats. Compared to controls, neonatal PEG40 exposure induced a significant TEAC reduction in the infantile rats. Protein carbonyls and lipoperoxide levels were not affected after any dose of PEG- b -PLA NP administration. In adult rats, PEG20 administration caused a significant decrease of protein carbonyl levels compared to controls. In infantile rats, both doses of PEG- b -PLA NP administration increased catalase, Gpx, and SOD activities compared to controls. Surprisingly, in adult rats, the activities of Gpx and SOD decreased significantly after administration of both doses of PEG- b -PLA NPs. Obtained data indicate a possible age-related association between the oxidative status and neonatal PEG- b -PLA NP administration in female rats.
- Published
- 2017
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22. Alternative methods in vitro for screening of endocrine disruptors.
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Dvořáková M, Kejlová K, Bendová H, Rucki M, Kohout P, Vavrouš A, and Jírová D
- Subjects
- Biological Assay, Cell Line, Estrogen Receptor alpha agonists, Estrogen Receptor alpha antagonists & inhibitors, Humans, Benzhydryl Compounds metabolism, Endocrine Disruptors metabolism, Estrogen Receptor alpha metabolism, Estrogens, Non-Steroidal metabolism, Phenols metabolism
- Abstract
Objectives: The aim of this study was to compare in silico data with results obtained in two alternative in vitro methods; and to investigate the potential endocrine activity of bisphenol A analogues. This article contributes to recent findings and brings up-to-date information on development of EU legislation and in vitro testing methods of endocrine disruption., Methods: In silico approach based on the OECD QSAR Toolbox was used for prediction of potential ligands of human estrogen receptor α. Estrogen Receptor Transactivation in vitro Assay to Detect Estrogen Receptor Agonists and Antagonists (OECD TG 455/457) using the VM7Luc4E2 (formerly designated BG1Luc4E2) cell line was performed for measurement of transactivation activity of the tested substances. Commercially available yeast-based microplate assay (XenoScreen YES/YAS, Xenometrix, Switzerland) for detection of compounds with estrogenic and androgenic agonistic/antagonistic activity was used as a comparative test to estrogen receptor transactivation assay (OECD TG 455/457) and for screening of the agonistic/antagonistic potential of human estrogen receptor and agonistic/antagonistic activity of tested compounds on human androgen receptor., Results: The study showed good correlation between the two in vitro assays and significant correlation with in silico data. All tested substances were identified as agonists for human estrogen receptor α by methods in silico and in vitro, four substances showed a potentially higher estrogenic activity comparing to bisphenol A, two substances were identified as very weak antagonists of human androgen receptor and one compound showed a potential of agonistic activity to human androgen receptor., Conclusions: The study contributes to recent findings and brings new in silico and in vitro data of bisphenol A analogues, revealing that these analogous substances should be further tested as they may show similar or higher activity in vivo comparing to bisphenol A, which has been recently legislatively regulated.
- Published
- 2016
23. Calcineurin role in porcine oocyte activation.
- Author
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Tůmová L, Chmelíková E, Žalmanová T, Kučerová-Chrpová V, Romar R, Dvořáková M, Hošková K, and Petr J
- Subjects
- Animals, Calcium Ionophores pharmacology, Exocytosis, Fertilization in Vitro, In Vitro Oocyte Maturation Techniques veterinary, Metaphase, Oocytes metabolism, Parthenogenesis physiology, Calcineurin pharmacology, Oocytes drug effects, Swine physiology
- Abstract
Calcineurin is required for oocyte exit from meiotic block in metaphase II (MII) stage in invertebrates and also in lower vertebrates. However, the role of calcineurin in mammalian oocyte activation is still unclear. The aim of this study was to determine whether calcineurin is involved in the processes regulating porcine oocyte activation. Indirect immunofluorescence demonstrated localization of both calcineurin subunits, CnA and CnB, especially in the cortex area of MII oocytes, in vitro fertilized and also parthenogenetically activated oocytes. After activation, the fluorescence intensity of the protein in the cortex area of oocytes remains unchanged; the protein calcineurin in the cytoplasm was recorded mainly around the pronuclei. Treatment of matured oocytes with calcineurin inhibitors, cyclosporin A (CsA) and hymenistatin I (HS-I), followed by activation with calcium ionophore A23187, significantly decreased the rate of activated oocytes compared to oocytes that were treated only with calcium ionophore (Ca-Io), (CsA+Ca-Io 25.0% v. Ca-Io 83.3%; HS-I+Ca-Io 32.5% v. Ca-Io 85.0%). Compared to the control, CsA treatment of matured oocytes followed by activation with Ca-Io did not affect the activity level of metaphase-promoting factor (MPF) and mitogen-activated protein kinase (MAPK) in activated oocytes evaluated by kinase activity assay. Simultaneous staining of calcineurin and cortical granule content in matured oocytes showed that calcineurin distributed in the cortical area of the oocyte has not been colocalized with cortical granules content. On the other hand, the calcineurin inhibition before parthenogenetic activation leads to a reduction of the cortical reaction level compared to oocytes that were not treated with CsA (complete exocytosis: CsA+Ca-Io 2.6% v. Ca-Io 83.9%; sum of cortical granule brightness: CsA + Ca-Io 0.69 v. Ca-Io 0.15). Our results showed that calcineurin is involved in the process of pig oocyte activation and cortical granule exocytosis; however this regulation seems to be MPF and MAPK independent.
- Published
- 2016
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24. [Levothyroxine therapy - factors influencing its outcome].
- Author
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Dvořáková M
- Subjects
- Drug Interactions, Feeding Behavior, Hormone Replacement Therapy, Humans, Intestinal Absorption, Medication Adherence, Hypothyroidism drug therapy, Thyroid Hormones therapeutic use, Thyroxine therapeutic use
- Abstract
The article gives an overview of the circumstances-eating habits, disorders of absorption in the intestinal and other disease, certain drugs and substances occurring in nature affecting the metabolism of thyroid hormones on many levels, thyroid disruptors, for which compensation may be healing broken thyroid function to be unsatisfactory in spite of following the rules of substitution treatment. Knowledge of these conditions and adapting to them timely by adjusting either the eating habits or thyroid hormone by adjusting benefits, allowing the patient to improve his subjective feelings from treatment and improving compliance.Key words: absorption - biological availability - compliance - levothyroxine therapy - drug interactions - nutritional habits - thyroid disruptors.
- Published
- 2016
25. The antioxidative properties of S-allyl cysteine not only influence somatic cells but also improve early embryo cleavage in pigs.
- Author
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Dvořáková M, Heroutová I, Němeček D, Adámková K, Krejčová T, Nevoral J, Kučerová Chrpová V, Petr J, and Sedmíková M
- Abstract
In vitro cultivation systems for oocytes and embryos are characterised by increased levels of reactive oxygen species (ROS), which can be balanced by the addition of suitable antioxidants. S-allyl cysteine (SAC) is a sulfur compound naturally occurring in garlic (Allium sativum), which is responsible for its high antioxidant properties. In this study, we demonstrated the capacity of SAC (0.1, 0.5 and 1.0 mM) to reduce levels of ROS in maturing oocytes significantly after 24 (reduced by 90.33, 82.87 and 91.62%, respectively) and 48 h (reduced by 86.35, 94.42 and 99.05%, respectively) cultivation, without leading to a disturbance of the standard course of meiotic maturation. Oocytes matured in the presence of SAC furthermore maintained reduced levels of ROS even 22 h after parthenogenic activation (reduced by 66.33, 61.64 and 57.80%, respectively). In these oocytes we also demonstrated a growth of early embryo cleavage rate (increased by 33.34, 35.00 and 35.00%, respectively). SAC may be a valuable supplement to cultivation media.
- Published
- 2016
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26. SGIP1 alters internalization and modulates signaling of activated cannabinoid receptor 1 in a biased manner.
- Author
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Hájková A, Techlovská Š, Dvořáková M, Chambers JN, Kumpošt J, Hubálková P, Prezeau L, and Blahos J
- Subjects
- Adaptor Proteins, Signal Transducing, Animals, Brain metabolism, Carrier Proteins genetics, Cell Membrane drug effects, Cell Membrane metabolism, Endocytosis drug effects, HEK293 Cells, Humans, MAP Kinase Signaling System physiology, Mice, Neurons metabolism, Rats, Wistar, Saccharomyces cerevisiae, Transfection, Two-Hybrid System Techniques, beta-Arrestin 2 metabolism, Carrier Proteins metabolism, Endocytosis physiology, Receptor, Cannabinoid, CB1 metabolism
- Abstract
Many diseases of the nervous system are accompanied by alterations in synaptic functions. Synaptic plasticity mediated by the endogenous cannabinoid system involves the activation of the cannabinoid receptor 1 (CB1R). The principles of CB1R signaling must be understood in detail for its therapeutic exploration. We detected the Src homology 3-domain growth factor receptor-bound 2-like (endophilin) interacting protein 1 (SGIP1) as a novel CB1R partner. SGIP1 is functionally linked to clathrin-mediated endocytosis and its overexpression in animals leads to an energy regulation imbalance resulting in obesity. We report that SGIP1 prevents the endocytosis of activated CB1R and that it alters signaling via the CB1R in a biased manner. CB1R mediated G-protein activation is selectively influenced by SGIP1, β-arrestin associated signaling is changed profoundly, most likely as a consequence of the prevention of the receptor's internalization elicited by SGIP1., (Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2016
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27. Transgelin is upregulated in stromal cells of lymph node positive breast cancer.
- Author
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Dvořáková M, Jeřábková J, Procházková I, Lenčo J, Nenutil R, and Bouchal P
- Subjects
- Biomarkers, Tumor metabolism, Breast Neoplasms pathology, Female, Gene Expression Regulation, Neoplastic, Humans, Neoplasm Grading, Neoplasm Proteins metabolism, Pilot Projects, Up-Regulation, Breast Neoplasms metabolism, Lymph Nodes metabolism, Lymph Nodes pathology, Microfilament Proteins metabolism, Muscle Proteins metabolism, Stromal Cells metabolism, Stromal Cells pathology
- Abstract
Transgelin and transgelin-2 have been discussed as potential markers of various cancers. Here we identified increased transgelin level in lymph node positive vs. negative, low grade primary breast cancer tissues using 2-DE in the cohort of 12 patients. We further clinically validated 2-DE results in an independent cohort of 48 low grade breast cancer patients through untargeted and targeted proteomics analysis (iTRAQ-2D-LC-MS/MS, mTRAQ-SRM), at transcript level and using immunohistochemistry. Another group of 48 high grade tumors of different breast cancer subtypes was analyzed together with the low grade samples to test transgelin specificity for low grade tumors and to study transgelin relation to known molecular markers and histological features. The results confirmed transgelin connection with the lymph node metastasis. As a marker of a reactive tumor stroma, transgelin can be connected with the higher risk of metastasis development. Moreover, we observed significant down-regulation of transgelin in high vs. low grade tumors caused by decreased content of stromal cells (mainly expressing transgelin) in high grade tumor tissue. We also analyzed expression of transgelin-2 in the second cohort using proteomics and immunohistochemistry. Transgelin-2 was mainly expressed by epithelial cancer cells and its levels were increased in metastatic and poorly differentiated tumors., Biological Significance: Both transgelin and transgelin-2 have been previously described as potential markers of many types of cancer. We are specifying this connection to metastatic affection of lymph nodes and cell differentiation in breast cancer. In the wider context, the results of our study highlight tumor stroma as a source of cancer biomarkers and point out how measured levels of tissue markers can actually reflect cellular feature of cancer mass., (Copyright © 2015 Elsevier B.V. All rights reserved.)
- Published
- 2016
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28. Characteristics of silver nanoparticles in vehicles for biological applications.
- Author
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Kejlová K, Kašpárková V, Krsek D, Jírová D, Kolářová H, Dvořáková M, Tománková K, and Mikulcová V
- Subjects
- Dynamic Light Scattering, Microscopy, Electron, Transmission, Particle Size, Pharmaceutical Vehicles, Metal Nanoparticles chemistry, Silver chemistry
- Abstract
Silver nanoparticles (AgNPs) have been used for decades as anti-bacterial agents in various industrial fields such as cosmetics, health industry, food storage, textile coatings and environmental applications, although their toxicity is not fully recognized yet. Antimicrobial and catalytic activity of AgNPs depends on their size as well as structure, shape, size distribution, and physico-chemical environment. The unique properties of AgNPs require novel or modified toxicological methods for evaluation of their toxic potential combined with robust analytical methods for characterization of nanoparticles applied in relevant vehicles, e.g., culture medium with/without serum and phosphate buffered saline., (Copyright © 2015 Elsevier B.V. All rights reserved.)
- Published
- 2015
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29. Endogenously produced hydrogen sulfide is involved in porcine oocyte maturation in vitro.
- Author
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Nevoral J, Žalmanová T, Zámostná K, Kott T, Kučerová-Chrpová V, Bodart JF, Gelaude A, Procházka R, Orsák M, Šulc M, Klein P, Dvořáková M, Weingartová I, Víghová A, Hošková K, Krejčová T, Jílek F, and Petr J
- Subjects
- Animals, Blotting, Western, Female, Hyaluronic Acid chemistry, Immunohistochemistry, Oocytes enzymology, Real-Time Polymerase Chain Reaction, Swine growth & development, Hydrogen Sulfide metabolism, Oocytes growth & development, Swine physiology
- Abstract
Hydrogen sulfide, one of three known gasotransmitters, is involved in physiological processes, including reproductive functions. Oocyte maturation and surrounding cumulus cell expansion play an essential role in female reproduction and subsequent embryonic development. Although the positive effects of exogenous hydrogen sulfide on maturing oocytes are well known, the role of endogenous hydrogen sulfide, which is physiologically released by enzymes, has not yet been described in oocytes. In this study, we observed the presence of Cystathionine β-Synthase (CBS), Cystathionine γ-Lyase (CTH) and 3-Mercaptopyruvate Sulfurtransferase (3-MPST), hydrogen sulfide-releasing enzymes, in porcine oocytes. Endogenous hydrogen sulfide production was detected in immature and matured oocytes as well as its requirement for meiotic maturation. Individual hydrogen sulfide-releasing enzymes seem to be capable of substituting for each other in hydrogen sulfide production. However, meiosis suppression by inhibition of all hydrogen sulfide-releasing enzymes is not irreversible and this effect is a result of M-Phase/Maturation Promoting Factor (MPF) and Mitogen-Activated Protein Kinase (MAPK) activity inhibition. Futhermore, cumulus expansion expressed by hyaluronic acid (HA) production is affected by the inhibition of hydrogen sulfide production. Moreover, quality changes of the expanded cumuli are indicated. These results demonstrate hydrogen sulfide involvement in oocyte maturation as well as cumulus expansion. As such, hydrogen sulfide appears to be an important cell messenger during mammalian oocyte meiosis and adequate cumulus expansion., (Copyright © 2015 Elsevier Inc. All rights reserved.)
- Published
- 2015
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30. Combined Proteomics and Transcriptomics Identifies Carboxypeptidase B1 and Nuclear Factor κB (NF-κB) Associated Proteins as Putative Biomarkers of Metastasis in Low Grade Breast Cancer.
- Author
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Bouchal P, Dvořáková M, Roumeliotis T, Bortlíček Z, Ihnatová I, Procházková I, Ho JT, Maryáš J, Imrichová H, Budinská E, Vyzula R, Garbis SD, Vojtěšek B, and Nenutil R
- Subjects
- Biomarkers, Tumor genetics, Databases, Protein, Female, Gene Expression Regulation, Neoplastic, Humans, Immunohistochemistry, Isotope Labeling, Kaplan-Meier Estimate, Neoplasm Grading, Neoplasm Metastasis, Reproducibility of Results, Biomarkers, Tumor metabolism, Breast Neoplasms genetics, Breast Neoplasms metabolism, Carboxypeptidase B metabolism, Gene Expression Profiling methods, NF-kappa B metabolism, Proteomics methods
- Abstract
Current prognostic factors are insufficient for precise risk-discrimination in breast cancer patients with low grade breast tumors, which, in disagreement with theoretical prognosis, occasionally form early lymph node metastasis. To identify markers for this group of patients, we employed iTRAQ-2DLC-MS/MS proteomics to 24 lymph node positive and 24 lymph node negative grade 1 luminal A primary breast tumors. Another group of 48 high-grade tumors (luminal B, triple negative, Her-2 subtypes) was also analyzed to investigate marker specificity for grade 1 luminal A tumors. From the total of 4405 proteins identified (FDR < 5%), the top 65 differentially expressed together with 30 previously identified and control markers were analyzed also at transcript level. Increased levels of carboxypeptidase B1 (CPB1), PDZ and LIM domain protein 2 (PDLIM2), and ring finger protein 25 (RNF25) were associated specifically with lymph node positive grade 1 tumors, whereas stathmin 1 (STMN1) and thymosin beta 10 (TMSB10) associated with aggressive tumor phenotype also in high grade tumors at both protein and transcript level. For CPB1, these differences were also observed by immunohistochemical analysis on tissue microarrays. Up-regulation of putative biomarkers in lymph node positive (versus negative) luminal A tumors was validated by gene expression analysis of an independent published data set (n = 343) for CPB1 (p = 0.00155), PDLIM2 (p = 0.02027) and RELA (p = 0.00015). Moreover, statistically significant connections with patient survival were identified in another public data set (n = 1678). Our findings indicate unique pro-metastatic mechanisms in grade 1 tumors that can include up-regulation of CPB1, activation of NF-κB pathway and changes in cell survival and cytoskeleton. These putative biomarkers have potential to identify the specific minor subpopulation of breast cancer patients with low grade tumors who are at higher than expected risk of recurrence and who would benefit from more intensive follow-up and may require more personalized therapy., (© 2015 by The American Society for Biochemistry and Molecular Biology, Inc.)
- Published
- 2015
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31. Metabotropic glutamate receptor 1 splice variants mGluR1a and mGluR1b combine in mGluR1a/b dimers in vivo.
- Author
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Techlovská Š, Chambers JN, Dvořáková M, Petralia RS, Wang YX, Hájková A, Nová A, Franková D, Prezeau L, and Blahos J
- Subjects
- Animals, Biological Transport, Active, Cells, Cultured, Dendritic Spines metabolism, Dimerization, Electrophoresis, Polyacrylamide Gel, HEK293 Cells, Humans, Immunoblotting, Immunohistochemistry, Male, Microscopy, Electron, Protein Isoforms, Rats, Rats, Sprague-Dawley, Rats, Wistar, Subcellular Fractions metabolism, Brain metabolism, Neurons metabolism, Receptors, Metabotropic Glutamate metabolism
- Abstract
The assembly of two covalently linked monomers into dimeric complexes is a prerequisite for metabotropic glutamate receptor 1 (mGluR1) function. The former concept of a strictly homodimeric subunit contribution in metabotropic glutamate receptor complexes has recently been brought into question. Alternative splicing of the GRM1 gene results in expression of variants that vary within their intracellular C-termini. Here we bring evidence that the short mGluR1b variant is found preferentially in a complex with the long mGluR1a variant in the rodent brain. The mGluR1a and mGluR1b variants distribution overlaps in Purkinje cells and the two variants colocalize in their spines. However mGluR1a and mGluR1b show distinct sub-cellular localization when expressed alone in neurons. We discovered that trafficking of mGluR1b to distal dendrites is reliant on its association with mGluR1a and that the long C-terminus of mGluR1a within the mGluR1a/b dimer is necessary for trafficking of the complex., (Copyright © 2014 Elsevier Ltd. All rights reserved.)
- Published
- 2014
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32. Thyroid carcinoma surgery in children and adolescents - 15 years experience surgery of pediatric thyroid carcinoma.
- Author
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Astl J, Chovanec M, Lukeš P, Katra R, Dvořáková M, Vlček P, Sýkorová P, and Betka J
- Subjects
- Adolescent, Carcinoma genetics, Carcinoma mortality, Carcinoma pathology, Child, Female, Humans, Hypocalcemia epidemiology, Iodine Radioisotopes therapeutic use, Lung Neoplasms secondary, Lymphatic Metastasis, Male, Mutation, Neck Dissection, Postoperative Complications epidemiology, Proto-Oncogene Proteins c-ret genetics, Radiotherapy, Adjuvant, Retrospective Studies, Thyroid Neoplasms genetics, Thyroid Neoplasms mortality, Thyroid Neoplasms pathology, Carcinoma surgery, Thyroid Neoplasms surgery, Thyroidectomy statistics & numerical data
- Abstract
Objectives: The purpose of this study is to evaluate the characteristics of thyroid gland surgery focusing on malignancies at the pediatric age with the main concern on treatment results and complications in extensive primary treatment., Methods: The records of all patients 18 years and younger with surgically treated thyroid diseases in the Prague Hospital, Motol, between 1991 and 2006 were retrospectively reviewed., Results: Thyroid surgery was performed on 148 pediatric patients (including 56 carcinomas). The youngest patient involved in the study was seven years old, the oldest patient 18 years old (mean 13.7 years). Most frequent histological cancer type was PTC (42 cases, 75%). Follicular cancer was diagnosed in five cases (8.9%) and medullar cancer in nine cases (16.1%). A prophylactic thyroidectomy was performed in three cases (5.4%) without clinical signs of thyroid tumor with diagnosed RET gene mutation., Conclusions: We consider total thyroidectomy with subsequent radioiodine ablation and TSH suppression as the basic approach in the treatment protocol of pediatric WDTC. The observed 100% recurrence-free and overall survival together with a low incidence of postoperative complications strongly supports the idea of a total thyroidectomy with selective neck dissection in the treatment of metastases of WDTC and MTC., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2014
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33. Novel FBN1 gene mutation and maternal germinal mosaicism as the cause of neonatal form of Marfan syndrome.
- Author
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Sípek A Jr, Grodecká L, Baxová A, Cibulková P, Dvořáková M, Mazurová S, Magner M, Zeman J, Honzík T, and Freiberger T
- Subjects
- Cyanosis genetics, Dyspnea genetics, Female, Fibrillin-1, Fibrillins, Humans, Infant, Newborn, Marfan Syndrome mortality, Mosaicism, Mutation, Phenotype, Amino Acid Sequence genetics, Marfan Syndrome genetics, Microfilament Proteins genetics, Sequence Deletion genetics
- Abstract
Marfan syndrome (MFS) is an autosomal dominant disorder caused by mutations in the fibrillin 1 gene (FBN1). Neonatal form of MFS is rare and is associated with severe phenotype and a poor prognosis. We report on a newborn girl with neonatal MFS who displayed cyanosis and dyspnea on the first day of life. The main clinical features included mitral and tricuspid valve insufficiency, aortic root dilatation, arachnodactyly, and loose skin. Despite the presence of severe and inoperable heart anomalies, the girl was quite stable on symptomatic treatment and lived up to the 7th month of age when she died due to cardiorespiratory failure. Molecular-genetic studies revealed a novel intronic c.4211-32_-13del mutation in the FBN1 gene. Subsequent in vitro splicing analysis showed this mutation led to exon 35 skipping, presumably resulting in a deletion of 42 amino acids (p.Leu1405_Asp1446del). Interestingly, this mutation is localized outside the region of exons 24-32, whose mutation is responsible for the substantial majority of cases of neonatal MFS. Although the family history of MFS was negative, the subsequent molecular genetic examination documented a mosaicism of the same mutation in the maternal blood cells (10-25% of genomic DNA) and the detailed clinical examination showed unilateral lens ectopy., (© 2014 Wiley Periodicals, Inc.)
- Published
- 2014
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34. The oncoprotein v-Myb activates transcription of Gremlin 2 during in vitro differentiation of the chicken neural crest to melanoblasts.
- Author
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Starostová M, Cermák V, Dvořáková M, Karafiát V, Kosla J, and Dvořák M
- Subjects
- Alleles, Animals, Avian Proteins genetics, Bone Morphogenetic Protein 5 genetics, Bone Morphogenetic Protein 5 metabolism, Cells, Cultured, Chick Embryo, Gene Expression Regulation, Intercellular Signaling Peptides and Proteins genetics, Intercellular Signaling Peptides and Proteins metabolism, Keratin-19 genetics, Keratin-19 metabolism, Oligonucleotide Array Sequence Analysis, Transcriptome, Avian Proteins metabolism, Cell Differentiation, Melanocytes physiology, Neural Crest cytology, Oncogene Proteins v-myb physiology, Transcriptional Activation
- Abstract
The neural crest (NC) is a transient dynamic structure of ectodermal origin, found in early vertebrate embryos. The multipotential NC cells migrate along well defined routes, differentiate to various cell types including melanocytes and participate in the formation of various permanent tissues. As there is only limited information about the molecular mechanisms controlling early events in melanocyte specification and development, we exploited the AMV v-Myb transcriptional regulator, which directs differentiation of in vitro chicken NC cells to the melanocyte lineage. This activity is strictly dependent on v-Myb specifically binding to the Myb recognition DNA element (MRE). The two tamoxifen-inducible v-Myb alleles were constructed one which recognizes the MRE and one which does not. These were activated in ex ovo NC cells, and the expression profiles of resulting cells were analyzed using Affymetrix microarrays and RT-PCR. These approaches revealed up-regulation of the BMP antagonist Gremlin 2 mRNA, and down-regulation of mRNAs encoding several epithelial genes including KRT19 as very early events following the activation of melanocyte differentiation by v-Myb. The enforced v-Myb expression in neural tubes of chicken embryos resulted in detectable presence of Gremlin 2 mRNA. However, expression of Gremlin 2 in NC cells did not promote formation of melanocytes suggesting that Gremlin 2 is not the master regulator of melanocytic differentiation., (Copyright © 2014. Published by Elsevier B.V.)
- Published
- 2014
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35. Proteomics in investigation of cancer metastasis: functional and clinical consequences and methodological challenges.
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Maryáš J, Faktor J, Dvořáková M, Struhárová I, Grell P, and Bouchal P
- Subjects
- Biomarkers, Tumor metabolism, Humans, Microdissection, Neoplasm Metastasis pathology, Neoplasms metabolism, Neoplasms pathology, Biomarkers, Tumor genetics, Neoplasm Metastasis genetics, Neoplasms genetics, Proteomics
- Abstract
Metastases are responsible for most of the cases of death in patients with solid tumors. There is thus an urgent clinical need of better understanding the exact molecular mechanisms and finding novel therapeutics targets and biomarkers of metastatic disease of various tumors. Metastases are formed in a complicated biological process called metastatic cascade. Up to now, proteomics has enabled the identification of number of metastasis-associated proteins and potential biomarkers in cancer tissues, microdissected cells, model systems, and secretomes. Expression profiles and biological role of key proteins were confirmed in verification and functional experiments. This communication reviews these observations and analyses the methodological aspects of the proteomics approaches used. Moreover, it reviews contribution of current proteomics in the field of functional characterization and interactome analysis of proteins involved in various events in metastatic cascade. It is evident that ongoing technical progress will further increase proteome coverage and sample capacity of proteomics technologies, giving complex answers to clinical and functional questions asked., (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2014
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36. Eye irritation hazard of chemicals and formulations assessed by methods in vitro.
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Jírová D, Kejlová K, Janoušek S, Bendová H, Malý M, Kolářová H, and Dvořáková M
- Subjects
- Animals, Humans, In Vitro Techniques, Cosmetics toxicity, Eye Diseases chemically induced, Irritants toxicity, Skin Diseases chemically induced
- Abstract
Background: The aim of this study was to compare human and animal skin irritation data with results of selected in vitro methods, including HET-CAM test, Neutral Red Release Assay, Neutral Red Uptake Assay and EpiOcular eye irritation test and with already existing data of eye irritation obtained from animal experiments., Methods: Chemicals employed in previous skin irritation validation studies and commercially available cosmetic formulations were subjected to further testing using in vitro methods Neutral Red Release (NRR) assay, Neutral Red Uptake (NRU) assay, HET-CAM test and EpiOcular assay., Results: The study revealed that skin irritants are not necessarily eye irritants; specifically volatile or solid materials may be misclassified. NRR assay provided false negative results in case of substances with fixative effect or not removable under standard washing procedure, emphasizing the role of microscopical evaluation as a crucial additional endpoint. Although overpredictive, HET-CAM test provided the lowest false negative rate. The most aggressive cosmetic formulation was correctly identified by EpiOcular assay, in accordance with NRU and NRR assays results, while HET-CAM test correctly identified the mildest formulation., Conclusions: Each of the in vitro methods is related to a specific endpoint of ocular irritation and provides only partial information on the mode of action of the tested material. Despite good reproducibility of individual in vitro assays, only the weight-of-evidence approach and results of multiple selected in vitro tests can allow for estimation of eye irritation hazard in vivo.
- Published
- 2014
37. DNA released by leukemic cells contributes to the disruption of the bone marrow microenvironment.
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Dvořáková M, Karafiát V, Pajer P, Kluzáková E, Jarkovská K, Peková S, Krutílková L, and Dvořák M
- Subjects
- Animals, Apoptosis, Cell Line, Tumor, Cell Nucleus metabolism, Chick Embryo, Chickens, DNA Damage, DNA Repair, Disease Progression, Histones metabolism, Humans, Neoplasm Transplantation, Nucleosomes metabolism, Stromal Cells physiology, Bone Marrow pathology, Bone Marrow Neoplasms pathology, DNA metabolism, Leukemia, Myeloid, Acute pathology, Tumor Microenvironment
- Abstract
Reciprocal interactions between a tumor and its microenvironment control expansion of tumor cells. Here we show a specific type of interaction in which blasts of experimental leukemia destroy the bone marrow (BM) structures and kill stromal cells. The in vitro experiments showed that the cytotoxic agent released by leukemic cells is the fragmented DNA derived from their genome and occurring in nucleosome-like complexes. This DNA entered nuclei of BM or other cells and induced H2A.X phosphorylation at serine 139, similar to double-strand break-inducing agents. There was a correlation between large amounts of acquired DNA and death of recipient cells. Moreover, the DNA integrated into chromosomal DNA of recipient cells. Primary human acute myeloid leukemia cells also released fragmented DNA that penetrated the nuclei of other cells both in vitro and in vivo. We suggest that DNA fragments released from leukemic and also perhaps other types of tumor cells can activate DNA repair mechanisms or death in recipient cells of a tumor microenvironment, depending on the amount of the acquired DNA. This can impair DNA stability and viability of tumor stromal cells, undermine homeostatic capacity of tumor microenvironment and facilitate tumor progression.
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- 2013
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38. Effect of natural polyphenols (Pycnogenol) on oxidative stress markers in children suffering from Crohn's disease--a pilot study.
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Koláček M, Muchová J, Dvořáková M, Paduchová Z, Žitňanová I, Čierna I, Országhová Z, Székyová D, Jajcaiová-Zedníčková N, Kovács L, and Ďuračková Z
- Subjects
- Adolescent, Amine Oxidase (Copper-Containing) metabolism, Antioxidants metabolism, Biomarkers metabolism, Child, Crohn Disease diagnosis, Crohn Disease drug therapy, Female, Flavonoids administration & dosage, Humans, Inflammation metabolism, Leukocyte L1 Antigen Complex metabolism, Male, Mesalamine administration & dosage, Mesalamine therapeutic use, Pilot Projects, Plant Extracts, Crohn Disease metabolism, Flavonoids pharmacology, Oxidative Stress drug effects
- Abstract
Crohn's disease (CD) is a nonspecific, chronic inflammatory disease of the gastrointestinal tract. It is supposed that in etiopathogenesis oxidative stress (OS) plays a role. However, its precise role in the active and non-active states of disease is not known yet. We conducted a pilot study focusing on the relationship between OS of CD in remission and the possibility to influence clinical parameters and markers of OS by polyphenolic extract, Pycnogenol® (Pyc). Compared to 15 healthy controls 15 pediatric CD patients (all were in remission according to their disease activity index - PCDAI) had reduced the activity of Cu/Zn-superoxide dismutase (SOD) and increased the oxidative damage to proteins. We found negative correlations between markers of inflammation (calprotectin, CRP) as well as between PCDAI and total antioxidant capacity (TAC). Activities of antioxidant enzymes, SOD, and glutathione peroxidase (GPX) negatively correlated with calprotectin and PCDAI. Pyc (2 mg/kg) positively influenced the parameters of OS in CD patients after 10 weeks of administration.
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- 2013
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39. Synthesis of cholic acid based calixpyrroles and porphyrins.
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Thi TH, Cardová L, Dvořáková M, Ročková D, and Drašar P
- Subjects
- Microwaves, Models, Molecular, Cholic Acid chemistry, Porphyrins chemical synthesis, Porphyrins chemistry, Pyrroles chemical synthesis, Pyrroles chemistry
- Abstract
New cholic acid based calix[4]pyrroles and porphyrins were prepared and their properties were studied. It was confirmed by spectral measurements that the superassembly of 5,15-bis(3α,7α,12α-trihydroxy-5β-cholan-24-yl)-10,20-diphenylporphyrin, the best candidate for this study from the conjugates prepared, may be influenced not only by the solvent mixture composition (polar/non-polar component ratio) but by time as well., (Copyright © 2012 Elsevier Inc. All rights reserved.)
- Published
- 2012
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40. Prevalence of obesity and metabolic syndrome in adult population of selected regions of the Czech Republic. Relation to eating habits and smoking.
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Vosátková M, Ceřovská J, Zamrazilová H, Hoskovcová P, Dvořáková M, and Zamrazil V
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- Adolescent, Adult, Aged, Czech Republic epidemiology, Female, Humans, Male, Metabolic Syndrome etiology, Middle Aged, Obesity etiology, Prevalence, Young Adult, Diet, Eating, Metabolic Syndrome epidemiology, Obesity epidemiology, Smoking epidemiology
- Abstract
Prevalence of the metabolic syndrome is around 25% in Europe but its occurrence grows in both genders with increasing age and weight. Lifestyle factors may contribute to the risk of developing metabolic syndrome. The objective of this study was to determine the relationship between metabolic syndrome and eating habits as well as length of sleep and smoking. Participants (519 women and 286 men aged 18-65 years) were chosen by random selection and questioned about their eating habits, sleep length and smoking. This information was combined with anthropometric and clinical parameters of metabolic syndrome. The female group was divided into two subgroups depending on climacteric stage (before and after menopause). Metabolic syndrome prevalence does not differ between regions in neither female (29.9%) nor male (32.5%) group. Body mass index ≥25 was detected in 50.4% of all women and 65.7% of men; 23.5% of all women and 21.7% men had body mass index ≥30. In conclusion, metabolic syndrome prevalence was proved to depend on eating habits and family heredity. Positive correlation between the above mentioned factors demonstrated itself in the total sample but not in individual regions. Metabolic syndrome prevalence in Czech adults is comparable with neighbouring countries. No significant interregional differences in metabolic syndrome prevalence within the Czech Republic were detected. In conclusion, relationship between eating habits and metabolic syndrome was confirmed.
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- 2012
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41. Oxidative stress in women with perimenopausal symptoms.
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Zitňanová I, Rakovan M, Paduchová Z, Dvořáková M, Andrezálová L, Muchová J, Simko M, Waczulíková I, and Duračková Z
- Subjects
- Adult, Aryldialkylphosphatase blood, Biomarkers blood, Case-Control Studies, DNA Damage, DNA Repair, Female, Guanine blood, Humans, Middle Aged, Premenopause blood, Surveys and Questionnaires, Antioxidants metabolism, Guanine analogs & derivatives, Lipid Peroxides blood, Oxidative Stress, Perimenopause blood
- Abstract
Objective: In this study, we examined the relationships between perimenopausal symptoms, biochemical parameters, and markers of oxidative stress in women in perimenopause and compared them with those of premenopausal women., Methods: Sixty-two women (age, 53.2 ± 5.7 y) with perimenopausal symptoms were recruited to participate in our study. The control group consisted of 18 women without perimenopausal symptoms (age, 40 ± 5 y).Clinical perimenopausal symptoms were evaluated via the questionnaire of the Menopausal Rating Scale. Our participants were checked for basic biochemical parameters. The oxidative status of our samples was determined through the examination of lipoperoxides, 8-oxoguanine (8-oxoG) levels, and the total antioxidant status (TAS)., Results: Perimenopausal women had higher total cholesterol values and lower paraoxonase-1 (PON1) activity compared to reference values. Other biochemical parameters as well as 8-oxoG levels were unchanged compared with those of healthy control women. Lipoperoxide levels were significantly increased compared with those of premenopausal women. We found an indirect correlation between PON1 arylesterase (PON1 A) activity and lipoperoxide levels, between PON1 A activity and atherogenic index, between age and TAS, and between age and 8-oxoG levels. DNA repair ability and the total antioxidant status of women in perimenopause were significantly increased compared with women in premenopause. Hypercholesterolemic women had significantly increased low-density lipoprotein cholesterol levels when compared with normocholesterolemic individuals, but these values were still within the reference range. Normocholesterolemic women had significantly decreased high-density lipoprotein cholesterol levels, below the reference range. We found no correlations between perimenopausal symptoms and biochemical parameters or oxidative stress markers., Conclusions: We found that women in perimenopause are under increased oxidative stress manifested by reduced PON1 A activity and elevated lipoperoxidation, DNA repair ability, and TAS. Nutritional antioxidant supplementation may be an effective approach in improving menopausal symptoms.
- Published
- 2011
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42. The impact of different operating conditions on membrane fouling and EPS production.
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Dvořák L, Gómez M, Dvořáková M, Růžičková I, and Wanner J
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- Biological Oxygen Demand Analysis, Kinetics, Pilot Projects, Pressure, Quaternary Ammonium Compounds analysis, Solubility, Biofouling, Biopolymers biosynthesis, Extracellular Space chemistry, Membranes, Artificial, Waste Disposal, Fluid methods
- Abstract
The main goal of this research was to investigate how different factors influence membrane fouling. The impact of the different concentrations of activated sludge and the amount of extracellular polymer substances (EPS) were monitored. Two pilot plants with submerged membrane modules (hollow fiber and flat sheet) were operated and the raw wastewater was used. Humic substances were identified as the major components of EPS in the activated sludge (more than 34%) in both pilot plants. As the basic constituent in permeate, humic substances were identified as the most dominant components in the effluent (61%) in both pilot plants. Conversely, proteins were mostly analyzed in permeate and supernatant below the detection limit. The total amount of EPS [mgg(-1) (VSS)] was similar for concentrations of activated sludge 6, 10 and 14 g L(-1). Carbohydrates were identified as the component of EPS which tends most to clog membranes., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Published
- 2011
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43. Uranium uptake by hydroponically cultivated crop plants.
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Soudek P, Petrová S, Benešová D, Dvořáková M, and Vaněk T
- Subjects
- Autoradiography, Biodegradation, Environmental, Crops, Agricultural growth & development, Hydroponics, Magnoliopsida growth & development, Magnoliopsida metabolism, Plant Roots growth & development, Soil Pollutants, Radioactive metabolism, Species Specificity, Uranium metabolism, Crops, Agricultural metabolism, Plant Roots metabolism, Soil Pollutants, Radioactive toxicity, Uranium toxicity
- Abstract
Hydroponicaly cultivated plants were grown on medium containing uranium. The appropriate concentrations of uranium for the experiments were selected on the basis of a standard ecotoxicity test. The most sensitive plant species was determined to be Lactuca sativa with an EC(50) value about 0.1mM. Cucumis sativa represented the most resistant plant to uranium (EC(50)=0.71 mM). Therefore, we used the uranium in a concentration range from 0.1 to 1mM. Twenty different plant species were tested in hydroponic solution supplemented by 0.1mM or 0.5mM uranium concentration. The uranium accumulation of these plants varied from 0.16 mg/g DW to 0.011 mg/g DW. The highest uranium uptake was determined for Zea mays and the lowest for Arabidopsis thaliana. The amount of accumulated uranium was strongly influenced by uranium concentration in the cultivation medium. Autoradiography showed that uranium is mainly localized in the root system of the plants tested. Additional experiments demonstrated the possibility of influencing the uranium uptake from the cultivation medium by amendments. Tartaric acid was able to increase uranium uptake by Brassica oleracea and Sinapis alba up to 2.8 times or 1.9 times, respectively. Phosphate deficiency increased uranium uptake up to 4.5 times or 3.9 times, respectively, by Brassica oleracea and S. alba. In the case of deficiency of iron or presence of cadmium ions we did not find any increase in uranium accumulation., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Published
- 2011
- Full Text
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44. How does pycnogenol® influence oxidative damage to DNA and its repair ability in elderly people?
- Author
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Dvořáková M, Paduchová Z, Muchová J, Duračková Z, and Collins AR
- Subjects
- 8-Hydroxy-2'-Deoxyguanosine analogs & derivatives, Comet Assay, Double-Blind Method, Female, Guanine analogs & derivatives, Guanine metabolism, Humans, Male, Middle Aged, Osteoarthritis, Knee metabolism, Oxidative Stress drug effects, Pinus, DNA Damage drug effects, DNA Repair drug effects, Flavonoids pharmacology, Plant Extracts pharmacology
- Abstract
Our purpose in this randomized, double blind, placebo controlled study was to find out the possible effect of a polyphenolic pine bark extract, Pycnogenol® (Pyc) on the level of 8-oxo-7,8-dihydroguanine (8-oxoG) as representative of oxidative damage to DNA and on the DNA repair ability of elderly people. According to our results, three months of Pyc administration had no effect on the level of oxidative damage to DNA or on repair ability, but we found a relationship between the level of 8-oxoG and repair ability of DNA in this group. To conclude, even if the positive effect of Pyc was not confirmed in the case of elderly people it is important to highlight the necessity of further investigations about the mechanisms of Pyc acting on different age groups.
- Published
- 2010
45. Sex hormone-binding globulin in congenital adrenal hyperplasia.
- Author
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Zamrazilová L, Dvořáková M, Lisá L, Stárka L, and Hampl R
- Abstract
Background: Sex hormone-binding globulin biosynthesis is influenced by three hormonal systems: gonadal, insular and thyroid. Congenital adrenal hyperplasia is characterized by overproduction of adrenal androgens associated with impaired insulin sensitivity, hyperinsulinemia and often also with hypothyroidism. Only scarce data are available concerning congenital adrenal hyperplasia. The objective of this study was to determine the distribution of sex hormone-binding globulin and free testosterone levels in these patients and to what extent these values correlate with actual 17-hydroxyprogesterone and androstenedione levels, which are commonly used for monitoring of treatment effectiveness., Materials and Methods: A total of 300 retrospective laboratory records of 78 males and boys and 456 records of 162 girls and premenopausal women with diagnosis of congenital adrenal hyperplasia under common substitution treatment were evaluated statistically. The data were divided artificially into groups of low, normal and high levels, with respect to physiological concentrations for each sex and age. The percentages of the total in each group were calculated., Results: Whereas an almost Gaussian distribution occurred for males, the data for females displayed a considerable shift to low sex hormone-binding globulin and accordingly high free testosterone levels. Sex hormone-binding globulin levels did not correlate with 17-hydroxyprogesterone., Conclusion: Low sex hormone-binding globulin levels in congenital adrenal hyperplasia, at least in females, reflect their involvement in insular and eventually thyroid axes, rather than the effectiveness of substitution.
- Published
- 2010
- Full Text
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46. Relationship between pituitary-thyroid axis hormones and anthropometric parameters in Czech adult population.
- Author
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Dvořáková M, Hill M, Čeřovská J, Pobišová Z, Bílek R, Hoskovcová P, Zamrazil V, and Hainer V
- Subjects
- Adolescent, Adult, Aged, Body Fat Distribution, Body Mass Index, Czech Republic, Female, Humans, Male, Middle Aged, Registries, Thyrotropin blood, Thyroxine blood, Triiodothyronine blood, Anthropometry, Body Composition, Pituitary Gland physiology, Thyroid Gland physiology, Thyroid Hormones blood
- Abstract
Although the relationships between thyroid function and anthropometric parameters were studied in patients with thyroid disorders and in morbidly obese subjects, such data in normal healthy population are scarce. In our study, relationships between factors of body composition, fat distribution and age with hormones of the pituitary-thyroid axis were evaluated in a large, randomly selected sample of normal adult Czech population comprising of 1012 men and 1625 women. Our results exhibited weak, but significant relationships between body composition, body fat distribution and the parameters of pituitary-thyroid axis. Some of these associations were gender-specific. As shown by backward stepwise regression model, body fat distribution evaluated by centrality index (subscapular/triceps skinfold ratio) was negatively associated with free triiodothyronine (fT3) serum levels only in women, while a positive correlation of fT3 with BMI was specific for men. BMI was inversely related to free thyroxine (fT4) concentrations in women but not in men. The centrality index (CI) was positively related to TSH levels in both genders. The fT3/fT4 ratio, reflecting deiodinase activity, was inversely related to age and positively related to BMI in both genders, while the highly significant negative correlation between CI and fT3/fT4 ratio was specific for women.
- Published
- 2008
- Full Text
- View/download PDF
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