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 21 for “"Human spermatozoa"”.
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Apoptotic markers in ejaculated human spermatozoa
… of apoptosis with morphological features in spermatozoa in the same samples. The three sample groups were identified as: teratozoospermic [G-pattern] (n=26), teratozoospermic [P-pattern] (n=98) and oligoteratozoospermic [Ppattern] (n=36). Standard semen analysis was conducted on the semen …
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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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CatSper: Characterisation in Human Spermatozoa and Clinical Significance
… for initiation of hyperactive motility in murine spermatozoa, and was previously identified to be disrupted in sperm from an infertile patient. However, little is known about the incidence of CatSper defects in the IVF (in-vitro fertilisation) patient population.<br/><br/>In the present study two …
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Compounds Modulating Calcium and Motility in Human Spermatozoa
… library that induced an increase in [Ca2+]i in human spermatozoa in-vitro. This thesis investigated the effect of this [Ca2+]i using techniques including CASA, Kremer tests and Flow cytometry to study compound effects on human spermatozoa motility and function. Some drugs demonstrated positive …
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Apoptosis Pathways: Presence and significance in Ejaculated Human Spermatozoa
… somatic cells are different.</p> <p>Ejaculated human sperm from patients and donors were separated into high and low motility fractions using Percoll™ gradients. Contaminating cells were removed using anti-CD45 conjugated paramagnetic beads. Fractions were divided into groups: staurosporine, …
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Choline Acetyltransferase and Carnitine Acetyltransferase Activity in Human Spermatozoa During Capacitation
<p>The regional distribution of ChAT activity in human spermatozoa is altered during in vitro capacitation and it correlates with the fertilizing potential of sperm.</p> <p>Regional immunoreactivity in human spermatozoa as assessed by fluorescent immunocytochemistry was compared with ChAT and CaAT …
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Novel method of selecting human spermatozoa for <em>In </em><em>Vitro </em>fertilization
… These characteristics help to assess how many spermatozoa are capable to get through the natural barriers of the female reproductive tract such as viscous cervical mucus, the uterus and into the fallopian tubes. The more spermatozoa are released into the vagina, and the more motile they are, …
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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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Investigating the clinical value of hyperactivation and intracellular calcium signalling of human spermatozoa and their value in drug screening
Confidential thesis. Abstract and full text under embargo until 12/03/2015.
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Microsurgical Fertilization of Mammalian Eggs: An Assessment of Clinical Utilization
… study evaluated the procedure in hamster and human eggs. Hamster sperm nuclei were microinjected into hamster eggs to determine the rate of abnormal fertilization and to ultrastructurally assess cellular damage by transmission electron microscopy. Hamster eggs were also injected with human …
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Acrosomal molecules exposure during human sperm capacitation
… of this study is to evaluate this event on human spermatozoa. Apart from zonadhesin, two other acrosomal molecules with a role in sperm-egg interaction, sp56 and sp32,were also studied for potential sperm surface exposure during capacitation.<br/>The first aim was to establish the optimum …
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Novel Modulators of Human Sperm Motility
… compounds that increase intracellular calcium in human spermatozoa. This project investigated these compounds, along with, 6 hit compounds previously identified from a HTS of a Chemogenomics library (246 compounds) for their potential to enhance sperm motility. One compound, Trequinsin …
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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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Utilization of nanostructured surfaces for sensing applications and the use of nanoentities for the fabrication of new materials
… a bioarray for the patterned immobilization of human spermatozoa cells. Such arrays would allow for the investigation of specific individual sperm cells. This could have a use in the field of artificial insemination. Chapter 6 utilizes citrate passivated Au nanoparticles to prepare composite …
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Mechanisms and consequences of DNA damage, response and apoptosis in spermatozoa.
DNA damage in spermatozoa is a crucial contributor to spontaneous abortion, severe genetic disease in the offspring and infertility. The chromatin of spermatozoa is highly compacted, transcriptionally and translationally silent, hence lacking DNA damage response (DDR). DDR foci follow within …
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Mechanisms and consequences of DNA damage, response and apoptosis in spermatozoa.
DNA damage in spermatozoa is a crucial contributor to spontaneous abortion, severe genetic disease in the offspring and infertility. The chromatin of spermatozoa is highly compacted, transcriptionally and translationally silent, hence lacking DNA damage response (DDR). DDR foci follow within …
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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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Zinc ion fluxes on the pathway to mammalian sperm fertilization competency
… ultimate maturation event preparing mammalian spermatozoa for fertilization, sperm capacitation, was first described in 1951, yet its regulatory mechanisms remain poorly understood. Here, we document a novel biological phenomenon of a unique Zn2+ distribution (further zinc signature) associated …
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Role of second generation phosphodiesterase inhibitors on mammalian sperm mobility
… were shown to enhance motility of human spermatozoa; however, contradictory results and stimulation of premature acrosome reaction has precluded their clinical use. Advancement in our knowledge have now made it clear that human sperm express several different PDEs and these are …
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