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Endogenous contaminants in food
Greifenthalová, Ivana ; Kočí, Radka (referee) ; Vítová, Eva (advisor)
This work is focused on the problematic of endogenous contaminants in foods. The overview of all important contaminants arising in foods during their processing and storage by influence of physical, chemical and microbiological factors is given here. The origin and occurrence in foods, biological effects, toxicity and possible health importance and also legislation requirements are described in single compounds. Finally, the possibilities of regulation of their production are shortly mentioned.
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Arsenic and arsenic species cycle in environment
Ševčíková, Kateřina ; Sommer, Lumír (referee) ; Dočekalová, Hana (advisor)
This bachelor thesis, based mostly on literature retrieval, deals with monitoring of individual arsenic compounds in the environment and is also reviewing methods used for their analysis. The experimental part is focused on determination of various arsenic in the Oncorhynchus mykiss tissue by HPLC-UV-HG-AFS. Obtained results showed that the arsenic was present in the tissue of the Oncorhynchus mykiss in form of arsenobetaine, which is common for fishes and other aquatic animals and is not toxic even for consuments.
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Cycling of mercury and mercury species in the environment
Finsterlová, Hana ; Diviš, Pavel (referee) ; Dočekalová, Hana (advisor)
This bachelor’s thesis deals with the role of mercury in an environment. It summarizes informations about properties of mercury and its species. The thesis is engaged in the presence of mercury in atmosphere, water, soil and sediments. It deals with individual mercury intakes into the environment, anthropogenic or natural, and it follows transport of mercury between individual components of environment. Part of this thesis is given to the accumulation of mercury and mercury species into plants and organisms. It points out the toxicity of mercury, mercury species, and their effect to human organism. In the last chapter there is a resume and description of the instrumantal methods, which are commonly used for determination mercury and its compounds.
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Vliv vybraných kardiovaskulárních léčiv nalézaných ve vodním prostředí na ryby
STEINBACH, Christoph Antonius
Cardiovascular pharmaceuticals are among the most prescribed drugs. As a result of the high consumption, these pharmaceuticals have been frequently detected in waste and surface waters. Verapamil, diltiazem and atenolol are very important representatives of cardiovascular pharmaceuticals; therefore, the present research focused on their acute and sub-chronic effects, bioconcentration, half-life time and metabolism in fish. Moreover, unified protocol for the quantitative assessment of histopathological alterations on the heart ventricle and coronary blood vessels employing heart index calculation was developed with the aim to better assess histopathological changes in fish heart which is one of the targets of cardiovascular pharmaceuticals and other chemicals. The effects caused by high concentrations of the studied substances, verapamil, diltiazem and atenolol, in fish can be considered similar to the therapeutic effects and side effects that are found in humans. The acute exposure to verapamil at the human therapeutic plasma level reduced the heart rate in common carp embryos and larvae. In addition, the acute and chronic exposure to this substance caused peripheral edema and gastrointestinal haemorrhage in carp. Similarly, the histological changes in heart and the blood vessels of the liver in diltiazem exposed rainbow trout suggested vasodilatation similar to the pharmacological effect of diltiazem in the human body. In rainbow trout sub-chronically exposed to atenolol at a human therapeutic blood plasma concentration, histopathological changes in the cardiovascular system were found. The bioconcentration of verapamil, diltiazem and atenolol in fish can be classified as low. Bioconcentration factor (BCF) of verapamil in whole body homogenates of common carp ranged between 6.6 and 16.6. The BCF of diltiazem was also relatively low (0.5-194) in analysed tissues of trout, following the order kidney liver muscle blood plasma. BCF of atenolol in rainbow trout tissues was the lowest among the tested substances (BCF = 0.002-0.27), following the order of liver > kidney > muscle. In the blood plasma, the concentration of atenolol was below the limit of quantification. Verapamil showed a longer half-life time (10.6 days) in fish compared to the human body, indicating the slow rate of biotransformation and/or elimination of verapamil in fish. Estimated half-life times of diltiazem in liver (1.5 h) and kidney (6.2 h) were in the same order of magnitudes as those determined for the human blood plasma. The half-life time of atenolol in trout was not studied, because of its very low bioconcentration. In diltiazem exposed rainbow trout, 8 groups of metabolites of diltiazem with 17 different isoforms were identified using liquid chromatography/high resolution mass spectrometry method. Diltiazem was found to undergo a biotransformation involving desmethylation, desacethylation and hydroxylation in fish. These results showed that diltiazem was metabolised in fish in a similar way like in the human body by desmethylation and desacethylation. On the other hand, hydroxylation, which was involved to a minor extent, seemed to be species specific. Verapamil had no effect on early life stages of common carp at the environmentally relevant concentration after one month lasting exposure. On the other hand, atenolol and diltiazem in environmentally realistic concentrations caused after 42-day exposure some physiological changes in rainbow trout. Namely, atenolol affected haematological and biochemical parameters of the blood in exposed rainbow trout and diltiazem caused changes in the activity of antioxidant enzymes in trout liver and gills. These data indicated that atenolol and diltiazem, when present in the aquatic environment, could be a source of sub-lethal detrimental effects in fish.
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The Toxicity of Radiotherapy for Head and Neck Tumours
NESEJTOVÁ, Šárka
Abstract The fundamental theoretical findings Head and neck tumours make up approximately 2-3% of all malignancies in our country. There is 4 times higher occurance at men population than women one. It is just smoking which belongs to important susceptible risk factors. The main therapeutic methods are operation, radiotherapy, chemotherapy, biotherapy and their combinations which carry, however, the risk of higher toxicity. The radiotherapy aim is to add the required dosage of ionizing radiation to target volume while maximally protecting treated organs. In order to decrease side effects the bearable radiation procedures are being developed which are trying to improve dosage distribution in target volume and decrease a dosage on surrounding good tissues. The level of treatment toxicity is one of the indicators for treatment effect evaluation. Basically we distinguish acute and chronic toxicity. The most often acute side effects of radiation of head and neck tumours are radiodermatitis, mucositis, xerostomia and dysphagia. Late toxicity is typically resulting in skin and mucous membrane atrophy, pharynx fibrosis and chronic decrease of salivation. Aim The aim of my thesis is to find out whether radiotherapy toxicity with my monitered sample is comparable with expert sources and whether its occurance is influenced by smoking. I have also done research if there is a difference between operated and non-operated patients with the level of side effects of radiation because the multimodal treatment is connected with a higher risk of toxicity. Research procedures My thesis is a theoretical research nature. In order to verify my hypothesis I have used the method of quantitative research with retrospective data collection from medical file archive of the Oncological department in the hospital České Budějovice a.s. In my selective sample I filed the patients who were being treated during 2009 - 2011 at the radiotherapeutical department of Hospital České Budějovice a.s. regardless age, sex, smokers or nonsmokers with an early degree of disease according to TNM classification. I have chosen the patients having neoplasm of larynx, oropharynx, tongue, hypopharynx or oral cavity as they are found at head and neck areas most often. The sample included both patients who had undergone only radiotherapy treatment and also those who had undergone adjuvant cancer therapy after a surgery. The common feature was a degree of side effect radiation and its dependance on smoking. The toxicity degree was evaluated by RTOG scoring for acute toxicity. Results In total I have evaluated 48 patients who met the criteria mentioned above. The Hample was made up of 88% men and 12% women . The average age of patients at the beginning of radiotherapy was 63,5. The most significant part were the ill with larynx tumours who made up 69% of all irradiated, the least occurance count hypopharynx /only 2%/. Smokers represent 29%, nonsmokers 11%, other patients were ex-smokers. 48% of patients were irradiated conventionally, 52% via an IMRT method. 31% of patients underwent adjuvant radiotherapy after surgery, the others only radiation. The most often side effect radiation occurred on skin, mucous membrane, pharynx, less occurance on salivary glands. Conclusion Ionizing radiation damage both malignant and good cells so we have to always consider damaging a good tissue while doing radiation. The sample of acute toxicity occurance seems to lower compared to an expert Study. A higher rate of acute side effects at smokers was not proved, however, the monitored sample shows a significant minority of nonsmokers so comparison does not have to be quite relevant. The nonoperated sample showed fewer side effects at early stage compared to the operated. It was not possible to statistically evaluate late toxicity.
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Consumer perception of additives
Hartmanová, Kateřina ; Horová, Olga (advisor) ; Bosák, Miroslav (referee)
The bachelor thesis focuses on the topic "Consumer perception of additives". In the theoretical part are characterized additives, their labeling and legislation. Another part deals with safety and toxicity of additives, where is also described a procedure for assessing the harmless of additives and potential health complications. Also, there is a list of the highest-risk additives and their groups. The theoretical part ends with the chapter dealing with the media and their effect on consumers regarding the additives. In the practical part is done a research regarding consumer awareness, their attitude to additives and habits they have by using a questionnaire survey. The aim of this thesis is to analyze consumer's attitude toward additives, whether he perceives it and if so, then how he perceives it. The goal is also to determine how consumers perceive the additive in terms of health and healthy lifestyles. Analysis of researched data is crucial to draw conclusions and to propose appropriate action in the field of additives.
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A simulated road accident of a tank truck in Ústí nad Labem resulting in chlorine leakage
LANGOVÁ, Regina
The main theme of the diploma thesis is simulated accident of a truck transporting pressure barrels with chlorine.The study is focused on evaluating the effects of the accident on the lives and health of the local population and assessing the risks (and the level of hazards) with the use of selected methods.In this study, the truck accident is described in detail and the risks are evaluated through using the IAEA-TECDOC-727 method, which is based on quantitative risk assessment of sources according to the level of hazard to lives.
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