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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Epigenetické a strukturální charakteristiky savčích oocytů a embryí: extrapolace pro humánní asistovanou reprodukci (ART) / Epigenetic and structural characteristics of mammalian oocytes and embryos: extrapolation for human ART

Langerová, Alena January 2014 (has links)
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...
12

Regulace subcelulárního vápníku během gametogeneze ryb

GOLPOUR DEHSARI, Amin January 2017 (has links)
Changes in the characteristics of spermatogenic and oogenic cells during gametogenesis may reflect a corresponding alteration in aspects of components such as calcium, which plays prominent roles in regulating a broad range of physiological events in animal reproduction. Basic information regarding distribution of intracellular calcium in different germ cells may provide better understanding of processes of reproduction in fish. The monthly testicular development in the cultured breeding stock of sterlet, Acipenser ruthenus, using histological and serum sex steroid was studied. Results showed four distinct phases including resting, pre-spawning, spawning and post-spawning. Hormonal profiles of 11-ketotestosterone (11-KT) showed peak, which indicated a seasonal pattern of gonadal development. The 11-KT concentration increased considerably during the spermatogenesis (pre-spawning phase) and remained quite high throughout the pre-spermiation period. In the final phase of testicular development (spawning phase), the 11-KT markedly dropped. This study provides basic knowledge of the reproductive biology in male sterlet and a complete guide for gonadal development, heretofore lacking in previous studies of sturgeon gonadal development. The intracellular distribution of calcium during different developmental stages of spermatogenesis was studied in sterlet, A. ruthenus, using a combined oxalate-pyroantimonate technique. The distribution of calcium was described in spermatogonium, spermatocyte, spermatid, and spermatozoon stages. Although calcium is appeared in the form of deposits in limited areas of the early stages cells (spermatogonium and spermatocyte), it is present as an unbound form in larger areas of spermatids and spermatozoa especially nucleus, which probably reflects changes in its physiological function and homeostasis of calcium during male gamete production. Similar to sterlet sturgeon, ultrastructural distribution of calcium during different developmental stages of spermatogenesis was described in a model organism, zebrafish (Danio rerio), using a combined oxalate-pyroantimonate technique. The subcellular distribution of intracellular calcium was detected as deposits mainly in the cytoplasm and the nucleus of the spermatogonium and spermatocyte. Interestingly, large amount of calcium was transformed from isolated deposits into an unbound pool (electrondense mass) within the nucleus of the spermatid and the spermatozoon. The alteration of intracellular calcium at different stage of D. rerio spermatogenesis can be related to specific function of each germ cell types during male gamete development. Unbound calcium in the nucleus of mature spermatozoon can be used for condensation of chromatin and induction of calcium wave during egg activation and fertilization. Using a combined oxalate-pyroantimonate technique, the subcellular distribution of calcium deposits during stages of oogenesis in zebrafish was described. Calcium deposits were localized at different organells within the egg during oocyte development. At the first stage of oocyte development (primary growth), calcium deposits were localized in the cytoplasm, mitochondria, nucleus, and follicular cells. At the cortical-alveolus stage, calcium particles were transported from follicular cells into the cortical alveoli. In the main stage of oocyte development (vitellogenic stage), some cortical alveoli were compacted and transformed from flocculent electron-lucent to electron-dense objects with the progression of the stage. Calcium deposits were transformed from larger to smaller particles, coinciding with compaction of cortical alveoli. As a conclusion, results of this study provide new and convergent insight into information about the regulation and functional roles of calcium during fish gametogenesis which simply describe facilitate release of calcium from related organelles (nucleus and cortical alveoli) as main internal stores of calcium for calcium transport.
13

Fenotypová studie Huntingtonové choroby TgHD miiniprasat: nástup a průběh reprodukčních a biochemických změn / Phenotypic study Huntington's disease TgHD minipigs: Appearance and progress of reproductive and biochemical changes

Bohuslavová, Božena January 2018 (has links)
Huntington's disease (HD) is one of the incurable and fatal diseases. HD belongs to the monogenic neurodegenerative diseases. According to the number of the CAG repetitions in the gene coding huntingtin, the onset of the disease is in childhood (5%), in the middle age, which is the most common (90%) and in the older age (5%). Beginning of the disease is manifested by changes in behavior; including problems with coordination and movement. Later, there is a psychological change. The disease leads to death. Until now, there is no effective curative treatment. In 2009, we created a model of the transgenic minipigs (TgHD) carrying the N - terminal part of the human mutant huntingtin (mtHtt) at our Institute in Liběchov. The number of offsprings and the resemblance in physiology and morphology between the pig (Sus scrofa) and humans (Homo sapiens) give us opportunities not only to study changes not only in central nerve organs, but also in peripheral tissues. The reproductive problems of TgHD boars were observed as the first phenotypic changes. Therefore, my work focuses at first on a study of the reproduction parameters of TgHD boars as well as ultrastructural, immunocytochemical and biochemical changes in testes and spermatozoa. In PhD thesis, I described in details the reproductive defects in TgHD...
14

Vliv ubiquitinace spermií v rámci časného embryonálního vývoje prasete / Effect of sperm ubiquitination in early embryonic development of porcine embryos

Petelák, Aleš January 2019 (has links)
The PhD thesis is focused on the effect of porcine sperm cell extracellular ubiquitination on early embryonic development up to the blastocyst stage after ICSI. In addition, it also presents a potential improvement of the technique of in vitro fertilization using oocyte incubation with ion channels regulators. To address these aims, we established an entirely novel methodology for sperm cell sorting using flow cytometry and subsequent cryopreservation. We determined the conditions for successful sperm cell sorting based on extracellular ubiquitination rate providing highly specific selection as well as sufficient numbers of viable sperms for fertilization using the ICSI method. Concerning the following cryopreservation, established methods were optimized to enable freezing of a minimal sperm cell suspension volume with low cell numbers. The performed experiments showed a direct relationship between the rate of extracellular ubiquitination and the capability of sperms to give rise to a properly developing embryo. Highly ubiquitinated sperm cells were less successful regarding the embryonic development to the blastocyst stage if compared with the lowly ubiquitinated group (6,2 % vs. 16,7 %, P<0,001). Interestingly, the rate of extracellular ubiquitination showed no effect on the pronuclear formation...
15

Vliv ubiquitinace spermií v rámci časného embryonálního vývoje prasete / Effect of sperm ubiquitination in early embryonic development of porcine embryos

Petelák, Aleš January 2019 (has links)
The PhD thesis is focused on the effect of porcine sperm cell extracellular ubiquitination on early embryonic development up to the blastocyst stage after ICSI. In addition, it also presents a potential improvement of the technique of in vitro fertilization using oocyte incubation with ion channels regulators. To address these aims, we established an entirely novel methodology for sperm cell sorting using flow cytometry and subsequent cryopreservation. We determined the conditions for successful sperm cell sorting based on extracellular ubiquitination rate providing highly specific selection as well as sufficient numbers of viable sperms for fertilization using the ICSI method. Concerning the following cryopreservation, established methods were optimized to enable freezing of a minimal sperm cell suspension volume with low cell numbers. The performed experiments showed a direct relationship between the rate of extracellular ubiquitination and the capability of sperms to give rise to a properly developing embryo. Highly ubiquitinated sperm cells were less successful regarding the embryonic development to the blastocyst stage if compared with the lowly ubiquitinated group (6,2 % vs. 16,7 %, P<0,001). Interestingly, the rate of extracellular ubiquitination showed no effect on the pronuclear formation...
16

Aspekty spermatologického vyšetření čerstvého ejakulátu beranů

Weberová, Gabriela January 2017 (has links)
The diploma thesis deals with the ram genital organs, hormonal regulation, sperm production and ejaculate. Practically were made preparations of rams before collecting semen, semen collection and ways of obtain semen. Further were evaluated quality native ram semen by macroscopically and microscopically methods. Evaluated material was obtained from zwartbles rams breed owned by Ing. Martin Hošek, Ph.D. All the ejaculate was immediately after collection examined macroscopically and microscopically. The volume of ejaculate, wave movement and activity of sperm were evaluated. Subsequently ejaculate transported was to the laboratory department of livestock reproduction of the Department of Animal Breeding Faculty of Agronomy, Mendel University in Brno. There was also assessed the concentration of sperm was made chill survival test when ejaculate was stored at 3 °C and the results were evaluated after 24 and 48 hours. There were also evaluated morphological coatings, which monitored defects of the head, acrosome defects, defects in the flagellum, immature sperm cells, sperm cells degeneration and normal sperm. The results show that the volume of the obtained sperm has an effect on genetic line, season, frequency of colection and age groups. For semen quality were proven decisive sampling sequence which had the effect of sperm concentration and survivability.
17

Olfaktorické receptory spermií u soliterních a sociálních hlodavců. / Sperm olfactory receptors in solitery and social rodents.

Klempt, Petr January 2013 (has links)
No description available.
18

Role reaktivních forem kyslíku a proteinové fosforylace na funkci spermií ryb

GAZO, Ievgeniia January 2015 (has links)
Spermatozoa of externally fertilizing fish species after releasing into aqueous environment are particularly vulnerable to damage mainly due to alterations in composition of media surrounding sperm. Among factors affecting spermatozoa movement in external medium are water pollutants, temperature, pH and osmotic conditions. The goal of this thesis was to investigate the possible effects of oxidative stress on sperm performance and intracellular signaling, particularly the effect of pollutants occurring in water environment. In addition the molecular mechanisms of stress response and motility activation for spermatozoa of several freshwater fish species were analyzed. Our results show that xenobiotics, such as vinclozolin, induce a dose-dependent reduction in sterlet (Acipenser ruthenus) spermatozoa motility and velocity at environmentally relevant concentrations. Increased levels of lipid oxidation (LO) and protein carbonylation (CP), as well as changes in antioxidant activity of superoxide dismutase (SOD) indicate the development of an oxidative stress in spermatozoa exposed to xenobiotic. Moreover, increased DNA fragmentation as well as a reduction of the level of ATP was observed in spermatozoa incubated with xenobiotic in vitro. These results demonstrated that sterlet spermatozoa are highly susceptible to the presence of pollutants, which induce excessive ROS production even at low concentrations. Further studies were performed in order to evaluate the role of ROS production in fish sperm and protective properties of seminal plasma. The ROS were generated in carp (Cyprinus carpio L.) spermatozoa by in vitro incubation with xanthine - xanthine oxidase system (X-XO). A time- and dose-dependent reduction in spermatozoa motility and velocity was observed as well as increased LO, CP and DNA fragmentation. Moreover, it was shown that O-linked N-acetylglucosamine transferase and septin-8-A changed their phosphorylation state on tyrosine residue, and acid phosphatase activity decreased in response to oxidative stress. On the other hand, catalase (CAT), superoxide dismutase (SOD), and glutathione (GTH) in combination with seminal plasma can reduce oxidative stress in carp spermatozoa and improve sperm quality. Our next study was applied to determine how the protein phosphorylation pattern changed after motility activation in carp and sterlet spermatozoa, where phosphorylated proteins are located in spermatozoon and to identify proteins involved in sperm motility. It was shown that the pattern of protein phosphorylation and their localization differs significantly between two species. Phosphorylation on serine and tyrosine residues, as well as protein kinase A (PKA) and protein kinase C (PKC) substrates play an important role in spermatozoa motility activation and regulation in both species. Numerous signaling proteins involved in carp and sterlet spermatozoa movement were identified in this study, giving a better understanding of molecular mechanisms underlying sperm motility. As a conclusion, the results of this study provide new data on the effect of xenobiotics and oxidative stress on fish spermatozoa motility, DNA integrity, lipid and protein oxidation, antioxidant defense system and intracellular signaling. These data proved the toxicity of water pollutants and ROS for fish spermatozoa and proposed the use of CAT, SOD, or GTH in combination with seminal plasma to reduce oxidative stress in these cells. Moreover, we identified many spermatozoa proteins involved in stress response and motility. In practice, the data presented in this thesis could be useful for elaboration of suitable medium for cryopreservation and artificial propagation of freshwater fish species.
19

Technologie zmrazování spermií býků ve vztahu k jejich přežitelnosti a oplozovací schopnosti / Freezing technology of bull sperm in relation to its survivability and fertilization ability

Doležalová, Martina January 2016 (has links)
The aim of optimalization the insemination doses production is to provide the highest fertilization ability of spermatozoa during the demanding proces of processing fresh semen and its subsequent cryopreservation. Temperature changes causes spermatozoa damage during the cooling and freezing. Spermatozoa is exposed to cold shock and many others limiting factors, which leads to cell death and therefore to decline of fertilization ability of thawed insemination doses. For increasing spermatozoa resistance, exactly the plasma membrane resistance against cold shock was fraction of egg yolk LDL cholesterol (low density lipoprotein) at various concentrations into the comercially produced diluents added. It is believed that LDL acts possitively to plasma membrane and helps to maintain the fertilization ability of spermatozoa after thawing. Following step in the proces of insemination doses production is slow cooling of diluted semen and equilibration, when the straws are store at cooling box for 30 minutes to 240 hours. This period is necessary to penetrate of certain diluent components into the spermatazoa also maintain the balance between their intracellular and extracellular concentration. Also important is subsequent freezing temperature gradient of insemination doses. The most suitable freezing method is based on computer controlled temperature decline in freezing chamber which allows the precise control of ice crystals formation that could tear and kill the cell. During 2012 to 2016 was repeatedly collected semen from the group of breeding bulls (n = 27, Holstein and Czech Fleckvieh breed) at AI centre. Semen which fulfill the standard entrance conditions in first step was evenly into several parts divided. For dilution the three types of comercially diluents AndroMed, Bioxcell and Triladyl with and without LDL addition were used. Into the diluents AndroMed and Bioxcell the concentration of LDL 4 %, 6 % and 8% into the dilent Triladyl 6 %, 8 % and 10 % was added. Diluted semen was filled into the glass capillares with volume 0,1 ml and temperature +4 °C. Subsequently the sample was placed to cold bath (0°C) for 10 minutes. Then the volume of capillare with physiological solution (37 °C) was mixed and for next 120 minutes was incubate. The effect of cold shock to proportion of live spermatozoa was evaluated by using Eosin and Nigrosine staining technique during heat test of spermatozoa survivability after spermatozoa heating and after 120 minutes of incubation. The more suitable semen diluents which provide the higher spermatozoa resistance against cold shock were AndroMed and Bioxcell. Together the possitive effect of LDL addition into the diluents to lower decrease of proportion of live spermatozoa during heat test was found (P<0.05). The most suitable LDL concentration which had a favorable influence at spermatozoa resistance against cold shock was 6 % in diluent Bioxcell. Values of the proportion of live sperm were higher at the beginning of the heat test (+1.31% to + 3.2%) and after 120 minute incubation (+5.82% to +8.41%) compared to other diluents with and without addition of LDL. In the next step the process of equilibration was optimized, is an important part of insemination doses production. The effect of the length of equilibration for subsequent fertilization ability of spermatozoa was evaluated using spermatozoa motility based of CASA and proportion of live spermatozoa after thawing and during heat survival test lasting 120 minutes (37 ° C). Suitable semen was diluted by comercially used diluent AndroMed based on soya lecithin, filled into the straws (0.25 ml), cooled and equilibrated in cooling box for 30, 120 and 240 minutes and freezed in programmable freezing box applying four types of freezing curves differing in temperature rate decline. There was used standard and by producer recommended 3. phase freezing curve, then 2. phase freezing curve, and 3. phase freezing curve with slower as well as rapid decline of temperature rate in freezing chamber, compared with standard freezing curve. The highest spermatozoa motility was found using 240 minutes of equilibration by +2.72% and +4.58% compared to other lengths of equilibration (P <0.05 to 0.01). The highest proportion of live spermatozoa was found using 120 minutes of equilibration (+6.87 % and +8.68 %). The highest average spermatozoa motility during heat test after thawing was achieved by using 2. phase freezing curve (from +2.97% to +10.37%, P <0.05), also in the proportion of live spermatozoa (from + 4.37% to +8.82%, P <0.01). When evaluating interaction between the length of equilibration and freezing curve (standard 3. phase and 2 . phase freezing curve), the highest average spermatozoa motility and proportion of live spermatozoa using 240 minutes of equilibration by both freezing curves was reached, there was no statistically significant differences. As well as, in all evaluated parts of this study the individual differences between ejaculate of bulls and within semen from one bull (P <0.05) as secondary effect were found. To maintain good fertilization ability of semen during cryopreservation is necessary to increase the spermatozoa resistance against cold shock using addition of correct concentration of LDL into the commercially used diluents AndroMed and Bioxcell. Subsequently the fertilization ability of insemination dose is influenced by cooling, the length of equilibration and freezing. The length of equilibration 120 minutes and more as well as gentle way of freezing according to freezing curve, which ensures a gradual decrease of temperature in freezing chamber provided the higher average spermatozoa motility and proportion of live spermatozoa.
20

Hodnocení kvalitativních a kvantitativních ukazatelů ejakulátu u hřebců

Hájková, Ivana January 2016 (has links)
Evaluation of semen quality is an important element in the evaluation of stallion fertility. Quality ejaculate produced in sufficient quantities is a prerequisite for successful insemination in horse breeding. To assess the quality of ejaculate is used by many laboratory evaluation methods. Selected methods are also engaged in this thesis. The basic parameters considerating in the ejaculate in this thesis are the evaluation of activity, sperm concentration and morphological sperm analysis. For using ejaculate in producing insemination doses need to be assessed volume of ejaculate too. Minimum volume of the ejaculate of stallions should be 20 ml. The activity of fresh semen should be at least 60 %. Normal sperm concentration value of stallions ejaculate is considered at least 100 × 106 in 1 ml of semen. The minimum amount of morphologically normal stallions sperm is required above the threshold value of 60 %. In this thesis we studied a group of stallions which were stabled in Zemský hřebčinec Tlumačov, s.p. Stallions were included in breeding season for 2015. Evaluation of quantitative and qualitative parameters were performed od 47 samples of fresh semen, which were collected from 12 stallions during the breeding season. Semen collecting was from April to July 2015. Immediately after each semen collecting was measured volume of ejaculate and sperm activity was recorded. To further evaluation were counting sperm concentration and morphology of sperm evaluation. For mophological analysis were preparations stained by two methods: B. T. Farelly staining and method Byghošť. The analysis was determined by the percentage of morphological sperm defects, which were divided into the following categories: acrosome defects, sperm head defects, sperm mid-piece defects, sperm tail defects, abnormal forms of sperm and immature sperm. The research also used a theoretical comparison of the two methods of stainings due to occurence of morphological defects and estimate the correlation relationships between qualitative and quantitative parameters of the ejaculated os stallions.

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