Undergraduate honors paper--Mount Holyoke College, 2005. Dept. of Biological Sciences. / Includes bibliographical references (leaves 74-79).

Thesis (Ph. D.)--University of Oregon, 2006. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 71-82). Also available for download via the World Wide Web; free to University of Oregon users.

Cytochrome P-450, the terminal oxidase of the metabolic mono-oxygenase system, is thought to exist in multiple forms, which have differing substrate specificities, and are variably inducible by different enzyme inducers. Many mutagens, themselves unreactive, require metabolic activation by one or more of these cytochrome P-450-dependent microsomal enzymes for mutagenic activity. Such mutagens may be detected in the Salmonella mutagenicity test only by the incorporation of an hepatic microsomal (59) fraction into the assay (as a first approximation to in vivo metabolism). Induction of the microsomal enzymes by different agents enhances the metabolic activation of mutagens; in fact, many mutagens are only detected when the 59 fraction has been induced by appropriate agents. Inducers of the phenobarbital-type are known to enhance microsomal steroid hydroxylation when administered at supraphysiological levels, inducers of several mono-oxygenase activities. In turn, the steroids, have been reported to be The inductive effects of the female sex-steroids and the combined effects of steroid and phenobarbital (PB) pretreatment on the metabolic activation of four mutagens have been investigated using the Salmonella assay. Female Sprague-Dawley rats were pret reated with 17a-oestradiol (E2) or progesterone (PRG) , at a level of either 1 mg/kg or 20 mg / kg daily for 14 days. A duplicate set of similarly pretreated groups were also induced with PB. Hepatic microsomal fractions were prepared from each group and incubated with each of the te st mutagens in the presence of a tester strain known to detect each particular type of mutagen. Induction of the hepatic metabolizing system by PB increased the activation of the mutagens significantly (as reflected by an increased number of revertant prototrophic S .typhimurium colonies). The administration of PRG also caused significant, and dose-dependent, induction of the activation of af l atoxin B1, benzo(a)pyrene, and dimethylnitrosamine. In general, E2 exhibited no inductive effect, but it did produce an increase in the activation of aflatoxin B1 (a reaction which is known to be catalysed by a mono-oxygenase prefe rentially inducible by PB). When use was made of a microsomal fraction that was prepared from animals which were both steroidpretreated and induced by PB, mutagenic activation was of the same order of magnitude as that observed when induction was brought about by PB alone. The absence of additive effect, taken together with the observations already mentioned, indicate that steroids induce the same cytochrome isozymes that are induced by PB. The implications of sex-hormonal regulation of the metabolic activation of mutagens are briefly discussed. / KMBT_363 / Adobe Acrobat 9.53 Paper Capture Plug-in

Steroid hormone receptors (SHRs) are well validated therapeutic targets in a number of diseases. Current therapies competitively antagonise the ligand binding domain (LBD), blocking activation of the receptor and downstream signalling pathways. However cross-reactivity can be seen amongst the antagonists of different SHRs eliciting unwanted side effects. Additionally the acquisition of resistance to current therapies in diseases such as prostate cancer limits their use. The amino-terminal domain (NTD) of SHRs provides an alternative target for antagonism by allowing potential therapies to block receptor transactivation and inhibit interactions with co-activator proteins. Reduced homology between different SHR NTDs also increases the specificity of drug interactions. However development of targeted therapies using rational drug design has been hindered by its intrinsically disordered structure. Establishing cell lines which stably express a SHR responsive reporter gene alongside variants of SHRs lacking the LBD provides a method by which small molecules specifically targeting the NTD of each receptor can be identified. This assay has been designed to overcome the barriers to drug discovery that are presented by an intrinsically disordered protein. The project follows the design, development, optimisation and implementation of a high throughput screening assay with the potential to identify novel small molecule inhibitors of SHRs. The applications of these inhibitors are highlighted throughout, with specific reference to their potential to inhibit the androgen receptor in prostate cancer.

Orientador: Luis Carlos Spolidório / Resumo: Hormônios esteroides sexuais participam de diversos eventos celulares e moleculares, e exercem influência sobre o epitélio e tecido conjuntivo do periodonto. A testosterona (T), principal hormônio androgênico, pode ser convertida em estradiol (E2) pela ação da enzima aromatase, ou em di-hidrotestosterona (DHT) pela ação da enzima 5α-redutase. Para elucidar o impacto de andrógenos sobre as células que compõem os tecidos conjuntivo e epitelial, fibroblastos e queratinócitos foram avaliados em relação aos efeitos de diferentes concentrações de T e DHT, além da exposição ao anastrozol (ANA), flutamida (FLU), fulvestranto (FUL), e às associações farmacológicas T+ANA, T+FLU e T+FUL. Os resultados do presente estudo indicaram que, de modo geral, hormônios esteroides androgênicos exercem efeitos opostos sobre eventos celulares de fibroblastos gengivais humano e células epiteliais HaCaT em cultura celular. Enquanto a T e a DHT agem promovendo o aumento da proliferação e atividade de fibroblastos, a exposição de células HaCaT a estes mesmos andrógenos resulta em inibição ou exiguidade do crescimento celular, atividade metabólica ou a capacidade de repovoamento da área de arranhão in vitro. Além disso, o tratamento farmacológico com ANA, FLU, FUL, e suas respectivas associações à T, parece influenciar eventos celulares de fibroblastos gengivais humano e células epiteliais HaCaT in vitro. / Abstract: Sex steroid hormones take part in different cellular and molecular process and exert their functions on the epithelium and connective tissue of the periodontium. Testosterone (T), the main androgenic hormone can be converted to estradiol (E2) through the aromatase enzyme action, or into dihydrotestosterone (DHT) by 5α-reductase activity. To elucidate the impact of androgens on the cells that constitute the connective and epithelial tissues, fibroblasts and keratinocytes were evaluated under the effects of different concentrations of T and DHT, besides to be both exposed to anastrozole (ANA), flutamide (FLU), fulvestrant (FUL), and the pharmacological associations T+ANA, T+FLU and T+FUL. The results of this study indicated that, in general, androgenic steroid hormones exert opposite effects on cellular events of human gingival fibroblasts and epithelial cells. While androgens act stimulating gingival fibroblasts, in HaCaT cells androgens promotes a shortage or inhibition of cell growth and activity. Furthermore, pharmacological treatment with ANA, FLU, FUL, and their associations to T, appears to influence cellular events of human gingival fibroblasts and HaCaT cells in vitro. / Mestre

No description available.

Orientador: Lúcia Helena Simões da Costa Paiva / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-19T17:10:16Z (GMT). No. of bitstreams: 1 Leao_RogeriodeBarrosFerreira_M.pdf: 2600347 bytes, checksum: 3c70f4a08f6a98df16d66375a85ccd5f (MD5) Previous issue date: 2012 / Resumo: Introdução: O tamoxifeno é utilizado no tratamento do câncer de mama receptor de estrogênio positivo. Seu mecanismo de ação está na inibição do crescimento das células malignas por antagonismo competitivo com estrógenos pelos receptores estrogênicos. A ação do tamoxifeno nestes receptores é variável e, dependendo do tecido, pode ter ação antagonista ou agonista. Em mulheres menopausadas usuárias de tamoxifeno, observa-se uma maior incidência de patologias endometriais, sendo o pólipo endometrial a alteração mais frequente. Sua patogênese não está bem estabelecida, mas parece estar relacionada a fatores hormonais. Objetivos: Comparar a expressão de receptor de estrógeno (RE) e de receptor de progesterona (RP) em pólipos endometriais de usuárias de tamoxifeno com pólipos endometriais e endométrio atrófico de não usuárias na pós-menopausa. Material e métodos: Entre mulheres submetidas à histeroscopia cirúrgica no Hospital da Mulher Prof. Dr. Aristodemo Pinotti - CAISM/UNICAMP de janeiro de 1998 a dezembro de 2008, foram selecionadas 84 mulheres na pós-menopausa usuárias de tamoxifeno, com pólipo endometrial benigno. Esse grupo foi comparado a 84 amostras de endométrio atrófico e 252 pólipos benignos de mulheres na pós-menopausa não usuárias de tamoxifeno e sem antecedente de terapia hormonal. As expressões de RE e RP foram avaliadas através de imuno-histoquímica segundo a porcentagem de células coradas, intensidade da coloração nuclear e escore final. A expressão de RE e RP no epitélio glandular e no estroma dos pólipos de usuárias de tamoxifeno foi comparada com o endométrio atrófico e os pólipos de não usuárias separadamente, utilizando o Teste de Mann-Whitney, corrigido pelo método de Bonferroni, teste exato de Fisher ou Qui-quadrado. Resultados: os pólipos de usuárias de tamoxifeno apresentaram maior expressão de RE e RP no epitélio glandular e estroma, em relação ao endométrio atrófico (p<0,0001). Em relação aos pólipos de não usuárias, as usuárias apresentaram maior expressão de RP no epitélio glandular (p=0,0014) e estroma (p=0,0056), não apresentando diferença significativa em relação ao RE. A maioria dos pólipos das usuárias e não usuárias de tamoxifeno apresentavam RE/RP positivos enquanto a maioria dos endométrios atróficos era RE/RP negativos. Conclusões: Os pólipos apresentam aumento frequente de RE, independentemente do uso do tamoxifeno. Por outro lado, os altos níveis de RP parecem consistentes com os efeitos agonistas da droga / Abstract: Introduction: Tamoxifen has been used for the treatment of strogen receptor-positive breast cancer. The effect of tamoxifen in breast cancer is the it inhibition cancer cell growth by competitive antagonism with strogen for strogen receptor (ER). The mechanism of action of tamoxifen in this receptor varies among different tissues, with antagonist effect (e.g. in breast) ou agonist (e.g. in endometrium). Thus, in menopausal women who use tamoxifen, a higher incidence of endometrial alterations is observed and endometrial polyps are the most common. The pathophysiology of endometrial polyp is still not definitely established but it seems to be related to hormone influence. Objectives: To compare the expression of estrogen receptors (ER) and progesterone receptors (PR) in endometrial polyps of tamoxifen users to atrophic endometrium and endometrial polyps of postmenopausal nonusers of tamoxifen. Material and methods: Among women undergoing surgical hysteroscopy in Hospital da Mulher Prof. Dr. Aristodemo Pinotti - CAISM/UNICAMP, from January 1998 to December 2008, 84 tamoxifen users with benign endometrial polyp were selected. This group was compared to 84 samples of atrophic endometrium and 252 benign polyps of postmenopausal women who were non-users of tamoxifen and no previous history of hormone therapy use. ER/PR expression was assessed by immunohistochemistry study according to the percentage of stained cells, intensity of nuclear color and final score. The expression ER and PR in the glandular epithelium and stroma of polyp tissue from tamoxifen users was compared to atrophic endometrium and polyps from non-users separately, using the Mann-Whitney test corrected by the Bonferroni method, Fisher's exct test or Chi-square test. Results: Polyps of tamoxifen users had a higher expression of ER and PR in the glandular epithelium and stroma, in relation to the atrophic endometrium (p<0.0001). Regarding polyps of women not treated with tamoxifen, users had a higher PR expression in the epithelium (p=0.0014) and stroma (p=0.0056), without any difference in ER expression. Most of polipys expressed ER/PR positives while atrophic endometrium were ER/PR negatives. Conclusions: Polyps frequently exhibit increase in ER expression, independent of the use of tamoxifen. High levels of PR seem to be consistent with agonist effects of the drug / Mestrado / Fisiopatologia Ginecológica / Mestre em Ciências da Saúde

Recent reports in the literature suggest that oral contraceptive steroid therapy may be implicated in the development of benign hepatic adenomas in women. Since estrogens and progestins are known to affect liver function, we studied effects of chronic administration of the oral contraceptive agents mestranol and norethindrone on various indices of hepatic integrity. Several hepatic mixed function oxidase activities were measured: benzo(a)pyrene hydroxylase, epoxide hydrase, aniline hydroxylase (Appendix II) and aminopyrlne N-demethylase (Appendix II). In addition, benzo(a)pyrene hydroxylase activity in lung tissue was measured. As an indication of whether metabolites of the contraceptive steroids were bound to liver macromolecules, irreversible binding of [³H]-benzopyrene was measured. Hepatic histopathology (light microscopy using hematoxylin and eosin stain and oil red 0 stain) was carried out to determine if functional alterations correlated with pathological changes in the liver. Comparisons were also made between ethanol treated and non-ethanol treated groups to determine if contraceptive steroid-associated hepatotoxiclty was enhanced by or would enhance, the hepatotoxiclty of ethanol administration. Female and male Wistar rats were pair-fed a nutritional liquid diet, Sustacal[sup R] (Mead Johnson) to which was added either sucrose or ethanol as 40% of calories. Oral contraceptive steroids were administered daily in the liquid, diet in the following doses: mestranol, 0.6 mg/kg per day, alone or in combination with norethindrone, 5.0 mg/kg per day. Initial short-term studies showed that the ethanol plus Sustacal[sup R] diet generally caused enzyme induction compared to the plain Sustacal[sup R] diet or the sucrose plus Sustacal[sup R] diet in animals treated for up to 6 weeks. Animals that were administered the contraceptive steroids for a similar time period also demonstrated hepatic microsomal enzyme induction. Enzyme activity in animals that received ethanol plus the contraceptive steroids was increased above that seen for each agent alone. Chronic studies showed that ethanol administration for 6 months produced hepatotoxiclty in both male and female rats. Hepatotoxiclty was observed functionally as decreased hepatic benzo(a)pyrene hydroxylase activity and histopathologically as increased fat accumulation in zone 3 of the liver lobules. It was found that administration of the contraceptive steroids to female rats tended to protect against ethanol-associated hepatotoxiclty. The protective effect was observed functionally as maintenance of control levels of hepatic benzo(a)pyrene hydroxylase activity and morphologically as lesser amounts of fat accumulation ln the liver. That is, there tended to be a correlation between the level of hepatic benzo(a)pyrene hydroxylase activity and histological fat accumulation as an indication of ethanol-associated hepatotoxiclty. A Sustacal associated phenomenon was evident in all animals in which hlstopathology was carried out. The "Sustacal effect" was observed, as mlcrodroplet fat accumulation ln zone 1 of the liver lobule. Contraceptive steroid treated females showed the least "Sustacal effect". Microsomal enzyme activity did not appear to be affected by the "Sustacal effect". It was concluded that the contraceptive steroids administered did not increase ethanol hepatotoxicity. Instead, it appeared that female sex steroids tended to attenuate ethanol-assoclated hepatotoxicity. There was no evidence to suggest that the oral contraceptive steroids were directly associated with overt hepatotoxicity. / Medicine, Faculty of / Anesthesiology, Pharmacology and Therapeutics, Department of / Graduate

Ovarian steroids assist in the development of the follicle and its enclosed oocyte as well as prepare the maternal environment for pregnancy. The objective of experiment 1 was to elucidate the differences between dominant follicles of each follicular wave in terms of intraollicular concentration of steroids after 4 d of dominance. Differences in blood perfusion between the dominant follicle of the first and second non-ovulatory wave were also examined. Follicular waves were monitored daily via ultrasonography from emergence to aspiration of the dominant follicle. It was determined that although the dominant follicles aspirated from ovulatory waves possessed a greater concentration of estradiol and a greater ratio of estradiol to progesterone, there was no difference in concentrations of steroid hormones or the ratio of estradiol to progesterone between dominant follicles collected from non-ovulatory waves and ovulatory waves. In a subset of cows, blood perfusion tended to be greater in dominant follicles that developed during the second non-ovulatory wave. The objective of experiment 2 was to determine whether or not the follicular wave had an effect on diameter of the ovulatory follicle, thickness of the endometrium, or subsequent pregnancy rates. Estrus was synchronized in females in such a way that females would ovulate the dominant follicle of the first or second follicular wave at timed artificial insemination. Diameter of the ovulatory follicle and endometrial thickness were not different between treatments; however, increased pregnancy rates were observed in heifers that ovulated the dominant follicle of the second follicular wave. There was no effect of follicular wave on pregnancy rates in cows. In conclusion, the role of follicular wave on the dominant follicle, maternal environment, and subsequent pregnancy rates is not fully understood. Additional experiments need to be conducted to further elucidate the differences in developmental potential of the oocyte and maternal environment when the dominant follicle of the first and second wave are destined to become the ovulatory follicle at timed insemination.

Thesis (Ph.D.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / The vagina is a key organ in the peripheral genital arousal response. In animal models, pelvic nerve stimulation increases vaginal wall compliance, blood flow and transudation of fluid. Decreases in ovarian steroids are known to induce structural changes in the vagina, and evidence is mounting that alterations in the hormonal milieu contribute to genital pathophysiology. To date, however, mechanisms by which sex steroids regulate vaginal arousal responses have not been adequately studied. Further, limited data are available on the effects of hormone replacement on tissue morphology, hormone receptor distribution and vaginal innervation. We propose that imbalances in sex steroid hormone levels alter the distribution, expression and actions of steroid receptors and neurotransmitters, leading to structural and functional changes in vaginal tissue and impairment the arousal response. The goal of this study was to assess dynamic changes in vaginal tissue structure with hormone deprivation and administration. Female Sprague-Dawley rats were used as an animal model. Intact animals served as controls. Ovariectomized animals were treated for a two week period with vehicle, estradiol, testosterone, progesterone, or a combination of estradiol plus testosterone or progesterone. To assess changes in vaginal physiology and morphology, physiological and histological techniques were used, including stereological analysis and immunohistochemistry for localization of hormone receptors and various neuronal markers. / 2031-01-01