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 105 for “"Androgens"”.
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Role of androgens in testicular development and dysgenesis
… were investigated in testes with suppressed androgens. In vitro studies were also used to investigate the role of androgens in Sertoli cell proliferation. Fetal rat testis explants were cultured with various chemicals designed to manipulate androgen action and Sertoli cell proliferation. …
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Regulation of ovarian progesterone biosynthesis by androgens and estrogen in the domestic hen
The hen lays eggs on successive days and then skips a day. The laying of these eggs, hence ovulation, occurs every 26 hour. The mechanism controlling this unique ovulatory cycle has not been defined. One level of control of this unique cycle resides in the ovary, specifically the ability of the …
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Effects of exogenous androgens on parental care behaviour in male bluegill sunfish (Lepomis macrochirus)
Research suggests an androgen mediated trade-off between nurturing and defensive behaviour during parental care. This research, however, comes from species with biparental care, where changes in behaviour of one parent can be compensated for by the other parent. I tested the validity of this …
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Ovarian hormones, but not androgens, mediate running-induced changes in high fat diet choice patterns in rats
… suggests that developmental factors or androgens might play a role in sustaining running-induced HF diet avoidance. Subsequently, Experiment 2 aimed to determine the role of androgens in the persistency of running-associated HF diet avoidance with sham-operated and orchiectomized (GDX) …
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Developmental Cell Death and Androgens Affect Neuron Number in the Primary Visual Cortex of Male and Female Rats
… cell death relative to control females. Thus, androgens are responsible for greater cell survival in the developing cortex.
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Synthesis and evaluation of fluorine-18 labeled androgens as in vivo imaging agents for prostatic cancer using PET
… four pairs of 16$\beta$- and 16$\alpha$-fluoro androgens, as well as two 20-fluoro androgens have been synthesized. The fluorination was achieved mainly by nucleophilic fluoride displacement of a triflate or a spirocyclic sulfate precursor, prepared by multistep synthesis.
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A test of the effects of androgens on immunity: no relationship between 11-keto testosterone and immune performance in bluegill sunfish (Lepomis macrochirus)
The posited immunosuppressive effects of androgens are a key component of the immunocompetence handicap hypothesis (ICHH). My thesis uses bluegill sunfish (Lepomis macrochirus) to test two predictions arising from this hypothesis: (1) natural concentrations of the androgen 11-keto testosterone …
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Design, Synthesis and Biological Properties of Fluorinated Estrogens, Progestins and Androgens, Potential Imaging Agents for Receptor-Positive Mammary and Prostate Tumors (fluorine-18)
Several estrogens fluorinated at the 17(alpha)- and 16(alpha)-positions were synthesized in the development of a potential fluorine-18 radiolabel useful as a means of quantifying estrogen receptor in receptor-positive mammary tumors. The affinities of the compounds for estrogen receptor were …
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Význam androgenů adrenálního původu u syndromu polycystických ovarií a hirsutismu
… glucocorticoids and, last but not least, androgens are synthesized here. The most abundant adrenal androgen is dehydroepiandrosterone sulfate, whose androgenic potency is not high, but it forms a reservoir in the circulation and can subsequently be metabolized to more potent androgens. …
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Neuromuscular Junctions in Androgen Sensitive Muscles: A Model for Synaptic Plasticity
… muscle and motoneurons are highly sensitive to androgens. Previous studies have shown that alterations in the levels of circulating androgens affect the activities of cholinergic enzymes in two androgen-sensitive muscles; the syringeal muscles of songbirds and the levator ani muscle of the rat. …
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The Role of Androgen Receptor Signalling in Endocrine Resistant Breast Cancer
… than ERα in BCa, and mediates the functions of androgens. In early forms of ERα-positive disease, AR is a positive indicator of prognostic outcome and suppresses ERα signalling. However, in ERα-negative disease AR has been demonstrated to drive cancer progression and recent evidence has …
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Study of the androgenic activity of the regenerating adrenal cortex.
… has been studied in adult male rats; circulating androgens were assessed through sexual accessory organ weights and zinc 65 uptake by the dorsolateral prostate. Acclimated intact and castrated animals were used as well as animals with regenerating cortices (bilateral - adrenal - enucleated) and …
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Eviction Behaviour in the Kalahari Meerkats
… metabolites and eviction behaviour. I find that androgens increase significantly during pregnancy in dominant females and the androgens levels are consistent within individuals over multiple pregnancies. Androgens levels appear to be associated with the offset of eviction however not the number …
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Effects of sex, free testosterone, and androgen receptor cag repeat number on spatial cognition and virtual navigation performance
… for three decades from the perspective that androgens contribute to this sex difference. To date, evidence to support the notion that androgens affect spatial cognition in healthy young individuals is balanced by evidence to the contrary. The present study sought to clarify the association …
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Sex Determination And Differentiation In The Common Snapping Turtle - A Reptile With Temperature-Dependent Sex Determination
… is well established that sex steroid hormones, androgens and estrogens, are important for sex determination and differentiation in TSD species. Yet, the role of androgens in these processes is not well understood. This dissertation addresses these questions in two parts. First, to identify …
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Androgen Regulation of Gene Expression Associated with Cell Growth and Neural Plasticity: Studies in Songbird Brain and the S115 Cell Line
<p>In order to characterize androgens' effects on the brain and behavior I identified the canary cDNA coding for the nuclear receptor for androgen. The sequence is very conserved over functional domains, but shows some divergence from the only other sequences known, those for rodents and man. The …
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Prostate Specific Membrane Antigen (PSMA): Immunoassay Development and Characterization of Transcriptional Regulation
… inducers of AP-1, EGF and TPA, and decreased by androgens. The PSMA promoter activity, as analyzed by luciferase assay, was also induced by EGF and cotransfected AP-1 proteins, but suppressed by androgens. The binding of AP-1 to three putative AP-l sites in the vicinity of the PSMA transcription …
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The role of progesterone receptor in hypothalamic kisspeptin neurons
… The polycystic ovaries are the source of androgens and high level of androgens induces the development of polycystic ovaries. In addition, hyperandrogenemia may increase GnRH release, potentially through the action on androgen receptor in kisspeptin neurons. Increased LH level secondary to …
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Rapid social regulation of 3β-HSD activity in the songbird brain
Rapid increases in plasma androgens are generally associated with short-term aggressive challenges in many breeding vertebrates. However, some animals such as song sparrows (Melospiza melodia) are aggressive year-round, even during the non-breeding season, when gonads are regressed and systemic …
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