National Repository of Grey Literature 116 records found  beginprevious72 - 81nextend  jump to record: Search took 0.00 seconds. 
Epigenetic and structural characteristics of mammalian oocytes and embryos: extrapolation for human ART
Langerová, Alena ; Fulka, Josef (advisor) ; Pěknicová, Jana (referee) ; Chod, Jiří (referee)
It is now more than 35 years since the first world test-tube baby, Louise Brown, was born (1978) in England and it is estimated that since then more than 4 000 000 of children were produced by in vitro fertilization (IVF) worldwide. The initial success of IVF was less than 20% in best clinics, but now it reaches about 40%. This is a consequence of introduction of new methods, standardization and exploitation of new manipulation and culture media, as well as the incorporation of research results. Nevertheless, the most important still remains the skill and experience of IVF clinics and IVF laboratories staff, especially their ability to critically evaluate the quality of biological material and to decide which cure and treatment are the best one. At least, some biological material (immature and low quality oocytes) can be used for training and also for some experiments aiming to explain some questions, which are not yet fully understood (for example aneuploidies in human oocytes and embryos). In addition, this training can facilitate the introduction of new progressive approaches and may also improve indirectly the quality of infertility treatments. The first part of thesis is focused on the quality evaluation of oocytes collected by aspiration from follicles of stimulated patients. For labeling...
Affecting sperm quality of sterile males by physiotherapeutic techniques
Borgesová, Monika ; Bezvodová, Vlasta (advisor) ; Horká, Bohumila (referee)
Author: Monika Borgesová Institution: Rehab clinic LF UK in Hradec Králové Topic of bachelor's thesis: Affecting sperm quality of sterile males by physiotherapeutic techniques Supervisor: Bc. Vlasta Bezvodová Number of pages: 104 Number of Attachments: 14 Year of vindication: 2013 Key words: Sterility, fertility, sperm (cell), spermatozoon, spermiogram (sperm analysis), physiotherapy Abstract: The bachelor's thesis concerns with male sterility, its causes, diagnosis and treatment options. The theoretical part contains anatomy of the pelvis and male pelvic organs, reproduction physiology, chaining of musculoskeletal system malfunctions, examinations of a man, treatment and regime measures. The theoretical part also gives examples of physiotherapy methods, which can be used for male sterility treating. Gained theoretical knowledge is applied in practice in a special part of the thesis. I dealt with 2 casuistries. One of them describes examination, therapy and development of spermiogram of functional male sterility, the other one focuses on men with structural damage of testicles.
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...
Physiological and hormonal mechanisms influencing ejaculate quality in birds
Mojžišová, Kateřina ; Tomášek, Oldřich (advisor) ; Svobodová, Jana (referee)
Sexual selection is an important mechanism of evolution. In addition to precopulatory sexual selection, arising when males compete for female partners, there is also postcopulatory sexual selection (sperm competition), when females copulate with more males. Even though most avian species are socially monogamous, most of them are also partially promiscuous. In such species, sperm competition is an important factor increasing variability in reproductive success between males. Male's success in sperm competition is primarily determined by sperm concentration, total sperm count and morphology and motility of spermatozoa. My bachelor thesis summarizes knowledge about the hormonal a physiological mechanisms that influence semen quality. This is especially the effect of sex and other hormones, physiological and oxidative stress, environmental conditions, antioxidant mechanism and composition of sperm cell membrane. Besides evaluating their influence on ejaculate quality on intraspecific level, I also describe their differences between avian species with respect to the differences of sperm competition.
Výživa plemenných býků
KOUBA, Jindřich
The aim of this thesis was the study of available publications covering the topic of breeding bulls nutrition, the analysis of the feed dose and the evaluation of the semen quantity and quality after addition of extruded flaxseed (EL) to the feed dose. 200 semen samples from 8 breeding bulls of the Czech Fleckvieh were proposed as the subject of observation. The influence of EL to the sperm motility and concentration and to the amount of semen was observed and evaluated. The positive effect was found out in all of the observed characteristics. Experimental group showed increase in the amount of semen in comparison to the control group, and the statistical analysis displayed a significant difference in the effect of the time factor (effect of the addition of EL) on the amount of semen within the groups. The sperm concentration in 1 mm3 of semen of the experimental group increased compared to the control group, but the difference was not statistically significant. The experimental group showed an increase in sperm activity and the time factor was statistically significant. From the results of this thesis follows that extruded flaxseed can be recommended as the suitable feed supplement for breeding bulls.
The influence of estrogens on mouse sperm capacitation and acrosome reaction in vitro
Tejnická, Magda ; Komrsková, Kateřina (advisor) ; Linhart, Otomar (referee)
There are an increasing amount of compounds in the environment that can have a negative effect on reproductive parameters in both male and female organism. There has been a worldwide decline of sperm quality during past decades and this fact lead to an increase of unnatural ways of conception through assisted reproduction techniques in the specialised centres. Natural estrogens are one of these compounds and they get into waste water after being excluded from the body by the urine. They get back into the human body from drinking water or from the food, and they can interfere with function of endogenous hormones in very low concentrations. For these reasons it is up to date to deal with the influence of these compounds on mammalian sperm. For many years, estrogens have been considered typically female sex hormones. It is now certain that they are also very important in the regulation of male reproduction. Endogenous estrogens in mammalian males are an important part of the endocrine system. Estrogens play an important role in the development of germ cells, spermatogenesis and processes leading to successful egg fertilization such as a capacitation or acrosomal reaction. Tyrosine phosphorylation is one of the essential steps for the properly ongoing process of capacitation in sperm followed by a...
Analysis of chromosomal aberrations in sperm by fluorescence in situ hybridization
Bendová, Petra ; Diblík, Jan (advisor) ; Novotná, Drahuše (referee)
The presented bachelor work is focused on the determination of frequency chromosomally abnormal sperm in the semen of healthy men (donors) with normal karyotype (46, XY). The important process, which plays an irreplaceable role in the development of numerical aberrations of chromosomes or structural abnormalities in the segregation of the gametes, is meiosis. Therefore, I devote much attention on meiosis in the theoretical part. The theoretical part is focused on the process of pre mature sperm (spermatogenesis), and the consequences of fertilize the oocyte by aneuploid sperm. In my work I present an overview of numerical abnormalities in autosomes and gonosomes and their frequency and distribution of gametes in healthy men. I also focused on the distribution and a brief description of structural aberrations affecting chromosomes and not least I paid attention on method of multicolor interphase fluorescence in situ hybridization, which in combination with sperm chromatin dekondenzation become irreplaceable and valuable research tool for rapid analysis of chromosomal abnormalities in large sperm samples. The experimental part of bachelor work deals with monitoring the frequency of selected numerical abnormalities in sperm samples of five donors aged 23 to 30 years with the use of I-FISH (fluorescence in situ...
Isolation and characterisation of oviductal proteins involved in formation of sperm oviductal reservoir in cow
Kračmerová, Jana ; Liberda, Jiří (advisor) ; Postlerová, Pavla (referee)
The oviduct plays an important role in the complex process of fertilization and in the early phase of embryo development. Isolation and characterization of some components of bovine oviduct participating in the formation of oviductal sperm reservoir was a subject of the present study. Two affinity sorbents containing immobilized components of bull seminal plasma (non-separated proteins of bull seminal plasma and their phosphorylcholine binding fraction) were prepared and used for the study of interaction of immobilized ligands with components of oviductal epithelium. Two types of preparation of oviductal membrane proteins of the isthmus region were isolated: complete membrane proteins and the apical fraction of membrane proteins. These preparations were separated using prepared affinity matrices. in both cases only an insignificant amount of proteins was found in the adsorbed fractions. Further attention has been paid to the identification of four protein zones detected after electrophoretic separation in the presence of SDS (rel. mol. wt. 15 500 - 18 500) in the fraction of apical membrane proteins. These proteins were identified after the electrophoretic separation and tryptic digestion using MS analysis as bovine histones H4, H2A typ 2-C, H2B typ 1-K a H3.3. Proteins identified as bovine...

National Repository of Grey Literature : 116 records found   beginprevious72 - 81nextend  jump to record:
Interested in being notified about new results for this query?
Subscribe to the RSS feed.