National Repository of Grey Literature 5 records found  Search took 0.00 seconds. 
Mutagenic and Antimutagenic Effect of Environmental Substances
Langová, Martina ; Vodička, Pavel (advisor) ; Sedmíková, Markéta (referee) ; Novotná, Božena (referee)
In the present study were used reference mutagens which effects mutagenic activity in prokaryotic and eukaryotic testing systems. Aflatoxin B1 (AFB1) is one of the most thoroughly studied and the well known mycotoxin with carcinogenic activity. 2-Amino-3-methylimidazol[4,5-f] quinoline (IQ) in isolated form has been used as another reference mutagen. These compounds are indirect acting genotoxins, i.e. need metabolic activation to exert genotoxic effect. As a third reference mutagen in the present study there has been chosen N-nitroso-N-methylurea (MNU) which is direct acting carcinogenic N-nitroso compound. The aim of the study was to investigate antimutagenic effects of ellagic acide (EA), resveratrol (RES), diallyl sulfide (DAS) and phenetyl isothiocyanate (PEITC) on the mutagenicity of the mutagens. The Ames test with Salmonella typhimurium TA98 and TA100 strains was used for the evaluation of antimutagenic effect of EA, RES, DAS and PEITC in vitro.
The effects of a hydrogen sulfide donor and garlic derivatives on the meiotic maturation and aging of porcine oocytes
Dvořáková, Markéta ; Sedmíková, Markéta (advisor) ; Miloslava, Miloslava (referee)
Oocyte meiotic maturation is a process of a transformation of the oocyte at the germinal vesicle stage to the oocyte at the stage of second meiotic metaphase. The process called oocyte aging occurs when oocytes are exposed after the completion of meiotic maturation to the prolonged cultivation. This process is characterized by a decrease in oocyte quality. The addition of suitable compounds into the cultivation medium could improve the quality of maturing and aging oocytes. Hydrogen sulfide is a gaseous molecule that is endogenously produced and fulfills signal function in organisms. Alliin and S-allyl cysteine are garlic derivatives that exhibit many positive effects on organisms. Many of them are mediated by their ability of releasing hydrogen sulfide. We hypothesize that the quality of oocytes in the in vitro cultivation system can be improved by the addition of the hydrogen sulfide donor and garlic derivatives into the cultivation medium. The aim of the study was to evaluate the effects of hydrogen sulfide and garlic derivatives on the meiotic maturation of oocytes, the effects of hydrogen sulfide on oocyte aging and the effects of cultivation with hydrogen sulfide and garlic derivatives on early embryonic development. It was found out that hydrogen sulfide donor accelerates oocyte nuclear maturation and causes an earlier increase of MPF and MAPK activities. Hydrogen sulfide donor improves activating potential of oocytes. It was found out that endogenous hydrogen sulfide production occurs during aging of procine oocytes and that the hydrogen sulfide production decreases after first 24 hours of prolonged cultivation. The inhibitors of hydrogen sulfide releasing enzymes impaired the quality of aged oocytes. Hydrogen sulfide donor completely suppressed fragmentation of oocytes exposed to prolonged cultivation and improved the quality of aged oocytes treated simultaneously with the inhibitors of hydrogen sulfide releasing enzymes. The presence of hydrogen sulfide donor during the prolonged cultivation of oocytes improved early embryonic development after parthenogenetic activation. It was found out that whereas alliin disrupts meiotic maturation of oocytes, S-allyl cystein has not influenced this process. S-allyl cysteine accelerated the onset of embryo cleavage and reduced ROS levels in maturing and parthenogenetically activated oocytes.
Expression of Heme oxygenase Isoforms during aging of porcine oocytes.
Poupalová, Michaela ; Sedmíková, Markéta (advisor) ; Lenka, Lenka (referee)
Quality and fertilization rate of oocytes matured in vitro conditions is essential for their use in biotechnology. Many morphological and functional changes occurs in oocytes during prolonged cultivation, which result in decreased fertilization rates and higher levels of apoptosis, polyspermy, parthenogenesis and chromosomal anomalies. These changes also have a negative effect on subsequent embryonic development. Understanding the mechanisms of oocyte aging could thus make a major contribution to the development of reproductive biotechnologies in livestock and human assisted reproduction. The enzyme heme oxygenase (HO) catalyzes the oxidative cleavage of heme to biliverdin, carbon monoxide (CO) and ferrous ions. There are two isoforms of heme oxygenase, i.e. HO 1 and HO 2. HO 1 has cytoprotective properties and in the cells is expressed especially in response to stress factors. HO 2 is responsible for basal production of CO. CO belongs to gasotransmitters, which are endogenously produced signaling gaseous molecules. Meaning of HO/CO system was proven in reproductive system of both males and females. Its importance in oocytes is not known. The aim of this thesis was to verify the hypothesis that the HO is expressed in porcine oocytes during their prolonged cultivation in vitro conditions and that the expression of both isoforms changes during aging. Oocytes were evaluated at the metaphase stage of the second meiotic division (MII) and three stages of aging according to the length of prolonged cultivation, i.e. 24, 48 and 72 hours. HO 1 and HO 2 were localized by immunocytochemistry method. By evaluating the experiments it was confirmed that both HO isoforms are expressed during aging in all evaluated areas, i.e. in the perichromosomal area, cortical area and cytoplasm. HO 1 is located mainly in the perichromosomal area and during aging occurs statistically significant increase in signal intensity. In the cortical area and the cytoplasm was detected statistically significant difference only in oocytes aging 72 hours and the signal intensity is weaker in these areas. In the case of HO 2 signal is evenly distributed throughout the oocyte and compared with the HO 1 the signal is significantly stronger. A statistically significant increase in signal intensity occurred between oocytes at the MII stage and the group of oocytes aging 24 hours. An expression of HO 2 compared with matured oocytes significantly increases during prolonged cultivation. A scientific hypothesis was confirmed in the case of both HO isoforms, i.e. HO 1 and HO 2 were localized in aging porcine oocytes and at the same time there is a change in expression during prolonged cultivation. From the results of experiments it can be assumed that products of enzymatic activity of HO-1 and HO-2, including CO are also present in oocytes, and therefore HO/CO system is probably related to the oocyte aging. The assumption is that HO 1 acts as a cytoprotective factor, which could have a possitive effect on oocyte quality. HO 2 is responsible for basal production of CO, but it may also play a role in the regulation of oxidative stress in oocytes. The data obtained should be investigated further with more experiments focused on localization and redistribution of both isoforms during oocyte aging. The subject of further research should also be a mechanism of action and specific function of HO 1 and HO 2 in oocytes.
The Incidence of Typical Diseases of Cavalier King Charles Spaniel Breed.
Homonická, Vendula ; Sedmíková, Markéta (advisor) ; Zdeňka, Zdeňka (referee)
Summary The thesis is focused on the incidence of inherited diseases such as the patellar luxation (LP), episodic falling syndrome (EF), dry eye and curly coat syndrome (CC/DE) and eye defects in the population of the Cavalier King Charles Spaniel (CKCHS) breed in the Czech Republic. It builds on the bachelor thesis focused on the incidence of degenerative heart disease called the myxomatous valve degeneration (MVD) in CKCHS. In 2003 the Czech Republic introduced a recovery breeding program following the example of some European countries, whose objective is the systematic monitoring of the CKCHS population restoring the health of the breed. The aim of the study was to evaluate the above-mentioned diseases in the CKCHS population of the Czech Republic and to find any potential correlation with sex, age and coat colour. LP is a polygenic and multifactorial disease. From a set of 360 individuals 16.7% males and 22.2% females were diagnosed positive for LP. The difference between the sexes and between age groups was not statistically significant. It was, however, found a weak correlation between diagnosed dislocation of the patella and coat colour. Most individuals diagnosed with LP were Black and Tan, while Tricolour was represented the least. Alleles for EF and CC/DE (EF/CC) are hereditary were not proven for any other breeds than CKCHS. Of the evaluated group of 337 individuals 25.9% males and 20.8% females were carriers of the EF/CC alleles. In the case of these diseases was also no statistically significant difference between males and females. Moderately strong correlation was found between EF/CC alleles presence and the coat colour. The majority of individuals positively diagnosed for EF/CC alleles were Black and Tan, and Ruby. Most individuals positive for the above mentioned alleles were aged up to three years, but statistically significant differences between age categories were not confirmed. Hereditary eye defects were from the whole set documented for only three individuals. Therefore, the correlation of the incidence of this disease with age, sex and coat colour was not statistically evaluated.
Canine Sensory Perception
Němečková, Markéta ; Sedmíková, Markéta (advisor) ; Chmelíková, Eva (referee)
My Bachelor Thesis Summarizes The Findings of The Current Scientific Literature about The Following: The Sensory Perception of Dogs, The Anatomical Structures that Provide Sensorry Perception as Well as The Mechanisms for Transferring Stimuli from The Outside Environment via Receptors and Sensory Organs to The Central Nervous System. It Analyses Dog's Senses, Specifically Sight, Taste, Smell, Hearing and Balance, Eyesight and Part also Deals with The Issue of Pain. It Presents The Individual Differences Senses the Dog from Other Mammals, Including Mankind and Shortly Using Dog's senses for People. The Conclusion is Devoted Primarily to The Ranking of Each Dog According to Relevance for Dog's Orientation in Everyday Life and also for The Use of Sensory Dog with Man.

See also: similar author names
1 Sedmíková, Magda
2 Sedmíková, Monika
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