|
|
Endogenně produkovaný sulfan v reprodukčním traktu samice ve vztahu k fertilizaci
BRICHCÍN, Jiří
The discovery of the mechanisms responsible for the proper process of fertilization and early embryonic development helps in the development of assisted human reproduction and technologies in livestock breeding. One of the regulatory mechanisms involved in reproduction is the gasotransmitter hydrogen sulfide, whose cellular signaling in germ cells is not fully described yet. According to the hypothesis, hydrogen sulfide is released in the female reproductive tract, where it physiologically affects sperm and is necessary for fertilization and the development of pronuclei. The aim was to verify the expression of hydrogen sulfide-releasing enzymes and the existence of a time-space gradient of hydrogen sulfide within the estrous cycle of the mouse (time axis) and to compare the expression profile of the fallopian tube ampulla and uterotubal junction (space axis). The experiments were performed on a laboratory mouse model (Mus musculus). The expression of hydrogen sulfide-releasing enzymes was studied by western blot. Hydrogen sulfide production was determined by colorimetry. The role of hydrogen sulfide in the fertilization process was studied by in vitro fertilization with hydrogen sulfide donor-treated sperm and by immunocytochemical staining of the zygotes. The expression of the known hydrogen sulfide-releasing enzymes, i.e. cystathionine--lyase (CTH), cystathionine-ß-synthase (CBS), and 3-mercaptopyruvate sulfurtransferase (3-MPST), was detected within the ovary and fallopian tube. Any enzymes did not show statistically significant differences in estrus and diestrus expression. Moreover, analogous results were found in the spatial axis; both the fallopian tube and the uterotubal junction expressed CTH, CBS, and 3-MPST enzymes, but no statistical differences were noted. Also, this applies to the production of hydrogen sulfide by these tissues. The effect of hydrogen sulfide on the fertilization process was analyzed according to lamin B1, a paternal pronucleus development marker. The performed analysis did not confirm the influence of the hydrogen sulfide donor on the development of the zygote pronuclei. The work showed that hydrogen sulfide is enzymatically released by the tissues of the female reproductive tract, regardless of the phase of the estrous cycle or the location in the fallopian tube. There is assumed a physiological influence of maternal-born hydrogen sulfide to sperm, which is capable of fertilization and leads to pronuclei development.
|
|
|
Possibilities of removing odors on the sewer network
Šlechtová, Tereza ; Malaník,, Stanislav (referee) ; Hluštík, Petr (advisor)
The aim of this diploma thesis is to research the possibilities of an odor regulation in a sewerage system. The first part of the thesis is devoted to legislation in sewege odor problematics. The second part includes description of the cause of the odor and methodology related to a hydrogen sulfide elimination either from sewerage atmosphere or straight from waste water. The next part examines the results of a survey, which was given to operators of the sewerage system. The survey examined the cause of an odor, its control and possible solutions of an odor in a sewerage system. Practical part is devoted to a given geographical area, where these problems have occurred the past. In this area the measuring of hydrogen sulfide presence took place by adding chemicals into waste water. From the collected data an evaluation was made. This can serve as a possible recommendation to sewege operators.
|
|
|
Options eliminate odors in sewer network
Žíla, Radim ; Malaník,, Stanislav (referee) ; Hluštík, Petr (advisor)
The diploma thesis focuses on the possibility of removing odor on the sewer network. The first part of the research describes how the odor is generally perceived and what legislation regulates its quantity in the air. The second part of the research focuses on problems of formation of smelting sulfate on the sewer network. This section describes the formation of sulfane as a major component of odor. Further disclosed are methods for its removal, and the ways in which the odor is measured. The practical part deals with laboratory testing of pre-selected fillings in order to determine their ability to remove odorous sulfane. In the second part, on-line measurements are made to determine the causes of sulphan formation in a given location.
|
|
|
Eliminating odors in the sewer network
Novotný, Jiří ; Malaník,, Stanislav (referee) ; Hluštík, Petr (advisor)
The diploma thesis focusses on the elimination of odor in the sewer system. Firstly, the paper contains the research in problematics of the origin, control and risks of the hydrogen sulfide for humans as well as for the sewer system. Secondly, the paper describes methods for hydrogen sulfide removal from water, air and in addition to that the selected sorbents are described in detail. Practical part deals with sorbent testing for hydrogen sulfide removal in laboratory environment. The practical part also follows up the odor in the particular area through sorption on sewer filters. From the measured data and from the results of the laboratory analyzes the consequences of the odor are evaluated and recommendations for the operator are presented.
|
|
|
Effect of hydrogen sulphide on aging of porcine oocytes in vitro
Krejčová, Tereza ; Petr, Jaroslav (advisor) ; Ješeta, Michal (referee)
Unfertilized or parthenogenetically non-activated porcine oocytes matured in vitro conditions are subjected to a process known as aging. During such development, porcine oocytes undergo the complex of the structural and functional changes, which can result in spontaneous parthenogenetic activation, fragmentation or lysis. After three days of culture in our condition, 23% of oocytes remained at the stage of metaphase II, 48% of oocytes were spontaneously parthenogenetically activated, 26% of oocytes were subjected to fragmentation and 3% of oocytes were lysed. The complete suppression of porcine oocyte fragmentation during the process of aging occurred during oocytes cultured in medium with sulphide donor Na2S in concentrations 150 µM and 300 µM. Inhibition of enzymes catalyzing the synthesis of hydrogen sulfide in the oocytes during the process of aging (cystathionine-gamma-lyase and cystathionine beta-synthase), iniciates earlier onset of oocytes fragmentation. The effect of both inhibitors could be completely reversed by using sulphide donor Na2S. The process of aging in porcine oocytes significantly reduces the success of the activation processes. Parthenogenetic activation occurred in 94% of pig oocytes, which were not subjected to aging. The proportion of activated oocytes after exposure to 24...
|
|
|
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.
|
|
|
The importance of monitoring post-mortem game meat changes
Santajová, Markéta ; Bušová, Milena (advisor) ; Daniel, Daniel (referee)
The main aim of the thesis is to discover the significance of parameters of postmortal changes of game, on which we may well base for the further appraisal in practice.
The theoretical part describes company for processing game, from which the samples for the experiment were taken. Furthermore, it incorporates the composition and the qualities of meat and the factors that affect the meat of game. A significant chapter describes postmortal processes and ways of meat spoilage.
The experimental part of the thesis measures both the pH and ammoniac postmortal indicators. As for the experiment, the measurement was carried out on two groups of samples coming from the ham of wild boar.
With regard to the results the indicators were proved to be measurable postmortal parameters by postmortal changes and consequent process ripening of meat. The figures between individual measurements increased, but the dependence on time cannot be made on grounds of the results. The figure of ammoniac increased during the measurement too, and we gained a concrete image of its content in the meat thanks to photometric method. The results were compared with the measurement of ammoniac of slaughter animals. For analysis volume of ammoniac in specimen of lean flesh was used traditional micro method according to Conway.
More profound analysis ought to be made for the appraisal of postmortal indicators. Next interesting parametres for determination of significance postmortal changes could be also enzymatic substance.
|
|
|
Intracellular distribution of hydrogen sulfide releasing enzymes in maturing porcine oocytes
Vondráková, Veronika ; Hošková, Kristýna (advisor) ; Tomáš, Tomáš (referee)
The study of the molecular mechanisms regulating reproductive processes is crucial for increasing the efficiency of reproductive biotechnologies that are often used in animal breeding. A key part of many biotechnological methods is the cultivation of oocytes, which simulates natural conditions in the ovaries. However this simulation is still imperfect and presents a limiting factor for successful formation of mammalian oocytes.capable of fertilization.
Meiotic maturation is influenced by many factors including for example gasotransmiter hydrogen sulfide (H2S). Until recently, hydrogen sulfide was known only as toxic gas polluting the environment. It was found that the hydrogen sulfide is at low concentrations important signaling molecule with a lot of physiological functions. Hydrogen sulfide is produced by enzymes CBS, CTH and 3-MPST in various tissues of the body, including the reproductive system.
We hypothesised that enzymes responsible for the endogenous production of hydrogen sulfide, CBS, CTH and 3-MPST, are present in porcine oocytes and their presence varies during meiotic maturation in cellular organelles. The goal of this study was to prove this hypothesis by cultivating porcine oocytes, detection of mitochondria, endoplasmic reticulum and hydrogen sulfide-releasing enzymes using imunocytochemistry and colocalization analysis.
Our results showed that enzymes releasing hydrogen sulfide, CBS, CTH and 3-MPST, are present in GV porcine oocytes and also in the oocytes matured to the MII stage, after 48 hours in vitro cultivation. We found that the distribution of these enzymes in cellular organelles in oocyte changed during meiotic maturation. There were significant changes in the distribution of enzymes 3-MPST and CBS in the mitochondria, levels of colocalization coefficients for enzyme 3-MPST increased, these coefficients for enzyme CBS decreased during meiotic maturation. In endoplasmic reticulum we found significant changes in the distribution of all three hydrogen sulfide-releasing enzymes. Levels of colocalitazion coefficients for CBS and 3-MPST increased, while levels of these coefficients for enzyme CTH decreased. Results of our experiments on porcine oocytes can help to clarify the role of gasotransmitter hydrogen sulfide during meiotic maturaion mammals of oocytes and are highly valueable because their possible application in breeding of farm animals and in human assisted reproduction.
|
|
|
Molecular mechanism of hydrogen sulfide action during meiotic maturation of porcine oocytes
Veselá, Andrea ; Hošková, Kristýna (advisor) ; Tomáš, Tomáš (referee)
At present reproductive biotechnology methods are on the rise, but their development and application in the broader management of reproduction is dependent on obtaining a sufficient number of quality oocytes cultured in vitro. The prerequisite for this requirement is the creation of the optimal conditions in the course of culturing oocytes.
Understanding and knowledge of the processes that occur in oocyte during maturation is an important and necessary condition for optimizing the process of culturing oocytes in vitro and gaining a sufficient number of good quality oocytes in metaphase II of meiotic division. A large number of mechanisms that affect and control oocyte maturation are known, however it cannot be claimed that this process has been fully explained and studied. One factor which has a potential role in the regulation of meiotic maturation of oocytes is gasotransmitter hydrogen sulfide (H2S), a critical signaling molecule of endogenous origin.
The study of H2S led to the hypothesis that H2S actively influences the course of meiotic maturation of pig oocytes by regulating key signaling cascades. The aim of this work was to determine the involvement of H2S in the regulation of the MEK1-MAPK signaling cascade, responsible for the initiation and progress of the meiotic maturation of oocytes and the MEK1-PARP-1 cascade as signaling that supports cell viability. For this purpose, pig oocytes cultured in modified media were used, supplemented with a specific combination of enzyme inhibitors (3Ki) or in a culture medium with donor H2S. The ocytes were then subjected to immunocytochemistry staining, fluorescence microscopy and image analysis.
The results show that H2S is involved in the regulation of meiotic maturation. It confirmed the hypothesis of the endogenous production of H2S in the course of the meiotic maturation of pig oocytes and the influence of the MAPK signaling cascade. Based on the results, it is however likely that the MEK1-PARP-1 signaling cascade is not affected by H2S, unlike MAPK signaling, comprising the mentioned MEK1 as superior kinase. MAPK kinase activity is significantly lower in oocytes after treatment 3Ki. Further experiments are for a detailed understanding of these regulatory pathways and for the proper verification of the mechanism of the effects of H2S necessary, in particular for a full understanding of the target control factors by the post-translational modification of S-sulfhydration.
|
|
|
Problems with sulphur and silicon in biogas
Holub, Radim ; Jecha, David (referee) ; Beňo, Zdeněk (advisor)
The main objective of this bachelor’s thesis is a description of a composition of biogas (BG) and contained undesirable components, which include especially sulphur and silicon compounds. In an introductory chapter is given a definition of the biogas, principle of its creation, chemical composition and a share of undesirable components. In following chapters are described single undesirable components, their properties and negative impact on parts of equipment using biogas. The following are the methods to reduce the critical concentration values of these components or their complete removal from biogas. In the thesis are also given practical solutions to eliminate these undesirable components.
|
guest ::
