Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 26 for “"Human Sperm"”.
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Analysis of Human Sperm Chromatin Integrity
… <p>The present study evaluated the integrity of human spermatozoal nuclear material in the two condensation stages of chromatin and chromosomes. Original semen samples (ORI) and their swim-up fractions (SW, selected for motility) from men of known (donors) and unknown (patients) fertility were …
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Novel Modulators of Human Sperm Motility
… and is most commonly characterised by asthenozoospermia (reduced sperm motility). Incredibly, there is currently no known treatment for this condition, and the only option is Artificial Reproduction Technology (ART) which is expensive and invasive. The development of a novel treatment would …
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Acrosomal molecules exposure during human sperm capacitation
At ejaculation sperm cells cannot fertilize. They need to undergo a series of molecular modifications to achieve competency. Surprisingly,molecular markers for identifying sperm populations competent to fertilize are not robust. However, recently an intra - acrosomal protein exposed at the …
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Organization of Human Sperm Chromosomes During Pronuclei Formation
… studies have demonstrated that chromosomes of human spermatozoa have well-defined spatial organization that includes preferred intranuclear positioning. The hypothesis of this dissertation is that sperm chromosome architecture participates in controlled transformation and activation of the …
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Modulation of calcium signalling in human sperm by nitric oxide
… studies were undertaken to assess the ability of human sperm and cumulus cells (surrounding the oocyte) to generate NO, investigate the mechanism of action of NO, the NO-mediated [Ca\(^{2+}\)]\(_i\) signalling pathways, the possible interaction of NO with progesterone (a product of cumulus) and …
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Hyperactivated motility in human sperm: regulation, function and significance in IVF
Hyperactivation is a movement pattern elicited by sperm in the female reproductive tract. The transition to hyperactivated movement is characterised by an increase in amplitude and a decrease in symmetry of flagellar bending. The resulting forceful, unequal waveforms produce a swimming style that …
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Measurement of cyclic nucleotides in human sperm: experimental and clinical application
The biochemical state of human sperm is critical for fertilisation potential, yet no convenient or reliable methods are available to assess essential second messengers. Cyclic nucleotides (cAMP and cGMP) play a crucial role as signalling molecules for capacitation, motility, and acrosome reaction …
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Investigating the effect of phosphodiesterase inhibitors on human sperm motility and function
… male infertility. This may include problems with sperm concentration, motility and/or morphology. Sperm motility defects are associated with most cases of male infertility and provide problems for sperm reaching, binding to and penetrating the oocyte therefore impacting on fertilisation success. …
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Hyperactivation of human sperm by 4-Aminopyridine: key role for mobilisation of stored Ca2+ in the sperm neck
Within the female reproductive tract mammalian sperm gradually develop hyperactivated motility, triggered by increased flagellar Ca2+ resulting in deep flagellar bends. Two sources of Ca2+ may contribute to the regulation of hyperactivation. Ca2+ influx at the plasma membrane is crucial and the …
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Characterization of the Biological Activities of Recombinant Fusion Protein Green Fluorescent Protein/Human Zona Pellucida Protein 3 (GFP/HZP3)
… the rhZP3 having direct binding activity with human sperm. Recombinant ZP3 generated from our previous study displayed binding activity with human sperm through indirect evidence from hemizona assay (HZA).</p> <p>This present study focused on the production of recombinant ZP3 with direct …
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Role of second generation phosphodiesterase inhibitors on mammalian sperm mobility
… and this is mostly characterised by reduced sperm motility (asthenozoospermia). Assisted Reproduction Technology (ART) is the only treatment option available for this condition. Over 20 years ago, non-selective phosphodiesterase inhibitors (PDEi), such as pentoxifylline, were shown to enhance …
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The Role of Glycoconjugates in Mediating Human Fertilization and Induction of Fetomaternal Tolerance
… the hemizona assay (HZA), a <em>in vitro</em> sperm-egg binding assay, we show that specific glycoconjugates known to inhibit immune cell interactions mediated by the selectins, potently block human sperm-egg binding. The selectin ligand sialyl Lewis<sup>x</sup> inhibits sperm binding in the …
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Protein Phosphatase 4 in human spermatozoa: investigations into location, regulatory subunits and role in motility
… process of maturation experienced by immature spermatozoa is the responsibility of post-translational modifications; a role of PKA in the regulation of sperm motility implies that protein phosphatases may be involved. The results presented in this thesis are the results of investigations into …
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Custom-Designed Biohybrid Micromotor for Potential Disease Treatment
… of custom-designed micromotors combined with sperm and their potential applications on targeted diseases treatment. By means of 2D and 3D lithography methods, microstructures with complex configurations can be fabricated for specific demands. Bovine and human sperm are both for the first time …
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The response of human spermatozoa to chemoattractants
… bourgeonal on [Ca\(^{2+}\)]i and chemotaxis in human sperm was investigated. Burgeonal induced a dose-dependent, slowly-developing tonic elevation in [Ca\(^{2+}\)]i, The response was dependent on capacitation. In low-Ca\(^{2+}\) or EGTA-buffered saline the response to bourgeonal was inhibited. …
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Effect of nanoparticles on human cells from healthy individuals and patients with respiratory diseases.
… effect of nanoparticles from these compounds in human germ cells. Thus the present study has examined their effects in the presence and absence of UV light in human sperm and compared responses to those obtained with human lymphocytes using the Comet assay to measure DNA damage. The effect of …
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Cryopreservation of Domestic Cat Epididymal Spermatozoa
… still effectively freeze domestic cat epididymal spermatozoa, for the purpose to sort spermatozoa into X and Y, using flow cytometry. In the first experiment we compared a TesT (Tes + Tris) 20% egg yolk extender (control) to a modified human sperm preservation medium (HSPM) and a Tris citrate …
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Examining the (patho)physiology of physiologically relevant ligands present in the male and female reproductive tracts
… regulation and function of the highly complex sperm cell. Understanding the critical roles of different proteins in maintaining sperm function is key to understanding the causes of sperm dysfunction. Currently, male infertility is clinically diagnosed by semen analysis, which results in a large …
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