National Repository of Grey Literature 47 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Interactive effects of carotenoid supplementation and oxidative stress on sperm morphology, sperm quality and spermatogenesis in the Zebra finches
Bílková, Karolína ; Albrecht, Tomáš (advisor) ; Jonáková, Věra (referee)
The phenotype-linked fertility hypothesis predicts that both, male carotenoid-based sexual ornamentation and their spermatozoa are phenotypically plastic and may be co-affected by the environment. One of the factors affecting their phenotype may be oxidative stress and the ability of organism to eliminate its effect. Oxidative stress may reduce sperm quality because sperm lack the ability to repair DNA, but it can also affect spermatogenesis itself. However, some substances may function as antioxidants, and thus eliminate effect of reactive oxygen species (oxidative stress) in the body. In this study, adult zebra finch males (Taeniopygia guttata) originating from the domesticated and recently wild-derived populations were exposed to the diquat (D), which enhances the oxidative stress, and carotenoid lutein (L), which could have an antioxidant function. Experimental design had factorial character 2x2 with a control (group L, D, LD, control). Neither oxidative stress, carotenoids, nor their interactions affected sperm morphology or velocity and it also did not increase abnormal sperm proportion in the ejaculate. However, the differences were observed at the molecular level, where by inducing the oxidative stress, the sperm had reduced signal intensity of acetylated α-tubulin in the sperm tails....
Functional role of HIF-1-regulated pathway in diabetic nephropathy
Nepomucká, Kateřina ; Konvalinka, Jan (advisor) ; Jonáková, Věra (referee)
Diabetic nephropathy (DN) remains the most common cause of end stage renal failure. Nearly 10% of patients with diabetes develop nephropathy. Hyperglycaemia in the kidneys leads to the activation of alternative metabolic pathways of glucose (glycation, activation of protein kinase C, and polyol pathway). These biochemical alterations lead to hypoxia and oxidative stress due to the increased formation of reactive oxygen species (ROS). Cellular response to hypoxia is controlled by hypoxia-induced factor 1 (HIF1), which is involved in the regulation of more than 800 genes. Target molecules of the HIF1 pathway participate in a wide range of physiological and pathological processes, e.g. angiogenesis, energy metabolism, apoptosis, migration, and proliferation. DN is associated with the pathological tissue remodelling process, epithelial-mesenchymal transition (EMT), and inflammation. HIF1 regulates key molecules of these pathological processes. EMT is regulated by TGFß1, CTGF, and SOX9. The progression of inflammation is regulated by VEGFA and AngII. The exact role of HIF1 signalling in the development of DN is not yet fully understood. This thesis evaluates the functional role of the HIF1 signalling pathway in the development of DN using a global heterozygous mutant with the deletion of the Hif1α gene....
Effect of estrogens and endocrine distruptors on mammalian sperm in vitro and male reproductive parameters in vivo
Děd, Lukáš ; Pěknicová, Jana (advisor) ; Jonáková, Věra (referee) ; Linhart, Otomar (referee)
The endocrine system is one of the most important regulatory systems in human and animal bodies and almost all physiological processes are regulated by it. Human and animal reproduction are largely regulated by different hormones and their proper and well regulated functions are essential for successful production of the gametes, fertilization and related processes, development of the embryo and fetus, initiation of puberty and production of the offspring. Estrogens have generally been considered as primarily female hormones. However, there is increasing evidence of their important impact on male reproductive functions. This was well documented by production of estrogen receptor knock-out male mice, which are infertile. Estrogens and estrogen receptors are also very frequent targets of endocrine disruption. Endocrine disruptors are natural or artificial compounds that, at certain doses, can interfere with the endocrine functions in human and wildlife. This interference can include specific binding to the hormonal receptor, influencing the production, elimination and transport of the natural hormones and also not well documented mechanisms including epigenetic regulations. In the presented work, our aim was to evaluate the effects of natural estrogens and endocrine disruptors on male reproductive...
The study of fluids and secretions from reproductive tracts of pig (Sus scrofa f. domestica) and cattle (Bos primigenius f. taurus)
Dráb, Tomáš ; Liberda, Jiří (advisor) ; Jonáková, Věra (referee) ; Ulčová-Gallová, Zdeňka (referee)
Interactions between proteins and saccharide moieties play an indispensable role in mammalian reproduction as they stand behind of such processes as maturation and mutual recognition of gametes and sperm oviductal reservoir formation. In my dissertation thesis I focused on activities of glycosidases from bovine and porcine follicular fluids and their changes connected with follicle development. Activities of five glycosidases were detected in tertiary and preovulatory follicles in both species. The most active enzymes were α-L-fucosidase in cow and α-D-mannosidase in sow and both enzymes also demonstrated the most pronounced increase in their activities during follicle maturation. Interestingly, both α-L-fucose in cow and α-D-mannose in sow were described as saccharides responsible for the formation of the sperm oviductal reservoir and we offered a hypothetical mechanism of synchronisation between sperm release from their reservoir with the time of ovulation based on a surge of activities of corresponding follicular glycosidases through the oviduct. Subsequently, it was demonstrated that β-D-galactosidase and α-D-mannosidase affect sperm-zona pellucida binding in pig, as they both decrease interaction between sperm receptors for zona pellucida and zona pellucida. This may explain the observation...
The Molecular mechanisms of sperm-egg fusion in mouse
Klinovská, Karolína ; Hortová, Kateřina (advisor) ; Jonáková, Věra (referee)
The mechanism of gamete fusion remains largely unknown on molecular level despite its indisputable significance. A few molecules requisite for membrane interaction are known, among them IZUMO1 on sperm and tetraspanin CD9 on egg. A concept of a large multitprotein complex on both membranes forming a fusion machinery is recently emerging. CD9 is expected to play a role in organizing egg membrane order and to interact laterally with other factors. On the other hand, IZUMO1 contains one immunoglobulin (Ig) domain, which is known for its interaction with various molecules and thus is expected to have a binding partner on the egg membrane. Ig domains are known for their involvement in interactions with Fc receptors and Fc receptor-like molecules, which makes these a potential partner for sperm in gamete binding and fusion. Recent experiments identified Fc receptor-like 3 as a candidate binding partner for sperm by one-bead one-compound assay. The aim of presented study was to assess the localization of FCRL3 in mouse eggs, together with its potential co-localization with IZUMO1 on complexes of zona-free eggs with bound sperm. In this study, FCRL3 molecule has been found across the cytoplasm, possibly in the intracytoplasmic membrane compartments of the cell, as well as on the egg membrane. Its presence...
Sperm morphology and molecular mechanism associated with sperm fertilizing ability in mice.
Šebková, Nataša ; Hortová, Kateřina (advisor) ; Jonáková, Věra (referee) ; Linhart, Otomar (referee)
The process of sperm capacitation and acrosome reaction (AR) are highly dynamic processes essential for the fertilization, including cytoskeleton proteins in the sperm head. The study of the distribution of actin, spectrin and α-tubulin in the head of representative mammalian sperm indicates that before and after the AR there were changes in the distribution of the cytoskeleton structures in the sperm head of all representatives, mainly in the apical part of the acrosome, but also in the equatorial and postacrosome part of the sperm head. The particularly well-studied actin cytoskeleton plays an important role during the capacitation and before and after the AR. Environmental estrogens can interfere with the function of endogenous hormones in very low concentrations. They can interact with specific receptors affecting several signalling pathways leading to sperm capacitation and AR. The effect of 17β-estradiol, estrone, estriol and synthetic 17α-ethynylestradiol was evaluated by the ratio of tyrosine phosphorylation and the state of the acrosome during in vitro capacitation in the sperm head. This study has provided the evidence that estrogens significantly stimulate capacitation progress in a concentration-dependent manner. Estrogens decrease number of sperm after the induced AR too. The raising...
The role of LIF gene mutations and the relative distribution of NK cells, NKT and T lymphocytes in follicular fluid and blood of women with different history of infertility
Křížan, Jiří ; Šíma, Petr (advisor) ; Jonáková, Věra (referee) ; Kročová, Zuzana (referee)
Charles University in Prague Faculty of Natural Sciences Summary of Ph.D. thesis The role of LIF gene mutations and the relative distribution of NK cells, NKT and T lymphocytes in follicular fluid and blood of women with different history of infertility Jiří Křížan Prague 2010 1 | P a g e Doctoral degree programs in biomedicine Charles University in Prague and the Academy of Sciences of the Czech Republic Programme: Biomedicine Chairman of the Subject Board: Doc. RNDr. Vladimír Holáň, Dr.Sc. Place of study: Institute of Microbiology, v.v.i., Academy of the Czech Sciences Vídeňská 1083, 142 20 Prague 4 phone: +420 296 442 318 Autor: Mgr. Jiří Křížan Supervisor: RNDr. Petr Šíma, CSc. The dissertation can be found at Dean's Office Faculty of Charles University in Prague 2 | P a g e CONTENTS Contents 2 Summary 3 1. Introduction 5 2. Hypotheses and aims 6 3. Material and methods 7 Material: 7 Methods: 8 4. Results 10 5. Discussion 12 6. Conclusion 15 7. References 16 Bibliography of Autor: 18 1. papers in extenso (thesis background) 18 2. papers in extenso (without regard to thesis) 19 3 | P a g e SUMMARY The aim of the dissertation thesis "The role of LIF gene mutations and the relative distribution of NK cells, NKT, and T lymphocytes in follicular fluid and blood of women with different history of infertility"...

National Repository of Grey Literature : 47 records found   1 - 10nextend  jump to record:
Interested in being notified about new results for this query?
Subscribe to the RSS feed.