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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.
1

Reproductive and Growth Responses of the Fathead Minnow (Pimephales Promelas) and Japanese Medaka (Oryzias Latipes) to the Synthetic Progestin, Norethindrone

Paulos, Peter M. 05 1900 (has links)
A commonly prescribed contraceptive, the synthetic progestin norethindrone (NET) inhibits ovulation in humans. However, ecotoxicological data are lacking. Preliminary tests produced an LC50 for NET of > 1.0 mg/L (96-hour, fathead minnow (FHM) and medaka) and a NOEC of 242.0 µg/L, a LOEC of 485.0 µg/L (7-day, growth for FHM and medaka). Reproductive testing revealed a LOEC for fecundity of 24.1 ng/L (21 days, medaka). Further testing confirmed the LOEC of 24.1 ng/L while defining a NOEC of 4.7 ng/L (28 days, medaka). Effect of NET in medaka life-cycle exposure at concentrations exceeding 4.7 ng/L was evident. Few females were present in the 24.7 ng/L exposure concentration, with none in the 104.6 ng/L. Egg production was significantly reduced at concentrations exceeding 4.7 ng/L. Additionally, weight, condition factor and somatic indices were significantly different in males exposed to concentrations exceeding 4.7 ng/L. For fecundity and sexual differentiation; the NOEC was 4.7 ng/L, the LOEC 24.6 ng/L; growth and somatic indices, the NOEC was more appropriately 0.9 ng/L, with effect evident at 4.7 ng/L. Sexual differentiation of the F1 population was similar to the F0. A defining result of this test was development of exceptionally large ovaries in NET- exposed female medaka, perhaps indicative of a threshold limit for exposure in these fish. Results of FHM life-cycle testing were similar, establishing a NOEC for fecundity of 0.9 ng/L, a LOEC of 4.8 ng/L. NET's inhibitory effect on gonadal development was obvious; GSI NOEC for males, 4.8 ng/L, and histological examination confirmed the presence of intersex development at elevated concentrations. Normal physical development and growth were impaired, generally at concentrations exceeding 24.1 ng/L. At exposure concentrations exceeding 4.8 ng/L, external sexual confirmation of fish was difficult; LOEC for finspot development in females, 4.8 ng/L. Sexual determination of the 97.1 ng/L exposure group was impossible; externally, all fish appeared male and internal examination revealed no gonadal development.
2

An in vitro investigation of the anti-inflammatory and immunosuppressive effects of the synthetic contraceptives medroxyprogesterone acetate (MPA) and norethisterone acetate (NET-A) /

Kriek, W. J. January 2005 (has links)
Thesis (MScMed)--University of Stellenbosch, 2005. / Bibliography. Also available via the Internet.
3

Comparative study of the molecular mechanism of action of the synthetic progestins, Medroxyprogesterone acetate and Norethisterone acetate

Africander, Donita Jean 03 1900 (has links)
Thesis (PhD (Biochemistry))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: Medroxyprogesterone acetate (MPA) and norethisterone (NET) and its derivatives (norethisterone enanthate (NET-EN); norethisterone acetate (NETA)), are used by millions of women as contraceptives and in hormone replacement therapy (HRT). Although both progestins are widely used, very little is known about their mechanism of action at the molecular level. In this thesis, the differential regulation of gene expression and molecular mechanism of action via different steroid receptors by these synthetic progestons, as compared to progesterone (Prog) was investigated in human cell lines. In the first part of the study, the effect of Prog, MPA and NET-A on the expression of endogenous cytokine genes was investigated in two epithelial cell lines of the human female genital tract, Ect1/E6E7 (an ectocervical cell line) and Vk2/E6E7 (a vaginal cell line). Quantitative realtime RT-PCR (QPCR) showed ligand-specific and cell-specific regulation of the interleukin (IL)-6, IL-8 and RANTES (Regulated-upon-Activation, Normal T cell Expressed and Secreted) genes with Prog, MPA and NET-A. Moreover, the repression of the TNF -induced RANTES gene by MPA in the Ect1/E6E7 cell line was found to be mediated by the androgen receptor (AR). The second part of the study focused on elucidating the androgenic activities of these two progestins, in comparison to Prog. Competitive binding in whole cells revealed that Prog, MPA and NET-A have a similar binding affinity for the hAR as the natural androgen dihydrotestosterone (DHT). Both transactivation and transrepression transcriptional assays demonstrate that, unlike Prog, MPA and NET-A are efficacious AR agonists, with activities comparable to DHT. Using a mammalian two-hydrid assay, it was shown that MPA and NET-A exert their androgenic actions by different mechanisms. NET-A, like DHT and other well-characterised androgens, induces the ligand-dependent interaction between the NH2- and COOH-terminal domains (N/C-interaction) of the AR independent of promoter-context, while MPA does this in a promoterdependent manner. In the third part of this study, competitive binding revealed that MPA and NET-A have a similar binding affinity to each other, but about a 100-fold lower affinity than Prog for the human mineralocorticoid receptor (hMR), while RU486 has an even lower affinity for the hMR. Promoter-reporter assays showed that MPA, NET-A and RU486 are all antagonists of the hMR, but unlike Prog, they have weak antagonistic activity. However, on the endogenous MR-regulated Orm-1 (a-glycolytic protein or orosomucoid-1) gene expressed in a rat cardiomyocyte cell line, NET-A and RU486, but not MPA, has similar antagonistic activity as Prog. This study is the first to show that, NET-A and RU486, but not MPA, can dissociate between transrepression and transactivation via the hMR. Taken together, these results show that natural Prog and the synthetic progestins, MPA and NET-A display differential promoter-, cell- and receptor-specific effects on gene expression. Furthermore they may have important implications for cervicovaginal immune function, cardiovascular and other physiological functions. / AFRIKAANSE OPSOMMING: Medroksieprogesteroon asetaat (MPA), noretisteroon (NET) en derivate daarvan (noretisteroon enantaat (NET-EN); noretisteroon asetaat (NET-A), word deur miljoene vroue gebruik as voorbehoedmiddels en vir hormoon vervangingsterapie (HVT). Tenspyte daarvan dat beide hierdie progestiene algemeen gebruik word, is min bekend oor hulle meganisme van werking op molekulêre vlak. In hierdie proefskrif word die differensiële regulering van geenuitdrukking asook die molekulêre meganisme van werking deur middel van steroïedreseptore van beide hierdie sintetiese progestiene, ondersoek, en vergelyk met progesteroon (Prog), in menslike sellyne. In die eerste deel van die studie is die effek van Prog, MPA en NET-A op die uitdrukking van endogene sitokinien gene ondersoek in twee epiteel sellyne van die menslike vroulike geslagskanaal, Ect1/E6E7 (‘n ektoservikale sellyn) en Vk2/E6E7 (‘n vaginale sellyn). Kwantitatiewe intydse RT-PKR het ligand-spesifieke en selspesifieke regulering van interleukien (IL)-6, IL-8 en RANTES (Regulering-na- Aktivering, Normale T-sel Uitgedrukte en Afgeskei) gene getoon met Prog, MPA en NET-A. Verder is gevind dat die onderdrukking van die TNF- - geïnduseerde RANTES geen deur MPA in die Ect1/E6E7 sellyn bemiddel word deur die androgeen reseptor (AR). Die tweede deel van die studie het gefokus op die toeligting van die androgeniese aktiwiteit van die twee progestiene in vergelyking met Prog. Kompeterende binding in volselle het getoon dat Prog, MPA en NET-A ‘n soortelyke bindings affiniteit vir die menslike AR as die natuurlike androgeen dehidrotestosteroon (DHT) vir die menslike AR het. Beide transaktiverings en transonderdrukkings transkripsionele analieses toon dat, anders as Prog, MPA en NET-A effektiewe AR agoniste is met aktiwiteite wat vergelykbaar is met die van DHT. Deur die gebruik van ‘n soogdier twee-hibried toets, kon gewys word dat MPA en NET-A hul androgeniese effekte uitoefen deur verskillende meganismes. NET-A, soos DHT en ander goed gekarakteriseerde androgene, induseer die ligand-afhanklike interaksie tussen die NH2- en COOH-terminale domeine (N/C-interaksie) van die AR, onafhanklik van die promoter-konteks. MPA, aan die ander kant, doen dit op ‘n promoter-afhanklike manier. In die derde deel van die studie het kompeterende binding getoon dat MPA en NETA soortelyke relatiewe bindings affiniteite vir die menslike mineralokortikoïed reseptor (hMR) het, maar dat hierdie affiniteit ongeveer 100-voud laer is as die van Prog en dat die affiniteit van RU486 vir hMR selfs nog laer is. Promoter-rapporteerder toetse het getoon dat MPA, NET-A en RU486 almal antagoniste van die hMR is, maar anders as Prog, is hierdie ‘n swak antagonistiese aktiwiteit. Nietemin, op die endogene MR-gereguleerde Orm-1 ( -glikolitiese proteïen of orosomukoïed-1) geen, uitgedruk in ‘n rot kardiomiosiet sellyn, het NET-A en RU486, maar nie MPA nie, ‘n soortgelyke antagonistiese aktiwiteit as Prog. Hierdie studie is die eerste om te wys dat NET-A en RU486, maar nie MPA nie, kan onderskei tussen transrepressie en transaktivering deur middel van die hMR. Samevattend toon die resultate dat natuurlike Prog en die sintetiese progestiene, MPA en NET-A, ‘n differentiële promoter-, sel- en reseptor-spesifieke effek op geenuitdrukking het. Verder mag die resultate belangrike implikasies vir servikovaginale immuunfunksie, asook kardiovaskulêre en ander fisiologiese funksies, inhou.
4

Effects of gonadal steroids on galanin and other neuropeptides in the rat brain /

Rugarn, Olof, January 1900 (has links) (PDF)
Diss. Linköping : Univ., 2001.
5

An in vitro investigation of the anti-inflammatory and immunosuppressive effects of the synthetic contraceptives medroxyprogesterone acetate (MPA) and norethisterone acetate (NET-A)

Kriek, W. J. 03 1900 (has links)
Thesis (MScMedSc (Pathology. Medical Microbiology))--University of Stellenbosch, 2005. / The aim of this study was to investigate the anti-inflammatory and immunosuppressive effects of the synthetic progestins, MPA and NET-A on human cells in vitro. These injectable contraceptives are used extensively throughout the world, including Africa. The potential of these two synthetic hormones to have certain immunosuppressive and GC properties have previously been shown. Therefore, it was of concern to us to investigate whether these two hormones could possibly demonstrate any of these GC-like properties at contraceptive doses. This was achieved by determining the effects of these two synthetic hormones in vitro on certain immunologic parameters. Chapter 1 is a literature review on MPA, NET and GCs. This chapter starts with a short introduction that sets the scene. The mode of action, effectiveness, sideeffects as well as previously reported relevant data on both MPA and NET-A is portrayed in this review. Research on the known GC, Dex, is also included in the section dealing with GCs, because this synthetic hormone was used as a comparative GC in all our experiments. This chapter soon makes the reader realize how much evidence exists that indicate the possible immunosuppressive effects these two contraceptive hormones, in particular MPA, could have. The possible anti-inflammatory or pro-inflammatory effects of MPA and NET-A are investigated in Chapter 2. This was done in vitro by measuring the effects of these two synthetic hormones on the inflammatory markers, IL-6 and TNFα, by means of ELISA. In this chapter we demonstrate that MPA, even at contraceptive doses, exhibits significant anti-inflammatory properties on both cytokines tested, while NETA displayed considerably less anti-inflammatory tendencies. In its true antiinflammatory manner, we found that Dex significantly inhibited the release of both inflammatory markers from human monocytes. In Chapter 3, we investigated the effects of MPA and NET-A on the activation of human lymphocytes. This was achieved by flow cytometric measurement of the expression of the activation membrane marker CD69 by CD4 and CD8 T cells. Here we discovered that MPA had a very significant inhibitory effect on the activation of both CD4+ and CD8+ T cells, while NET-A only significantly inhibited the activation of CD8+ T cells. In addition, we found that the inhibition of CD4+ and CD8+ T cell activation by MPA was more or less the same as the known GC, Dex, and in some cases even more potent. Chapter 4 consists of an investigation of the effects of MPA and NET-A on the cytokines belonging to TH1 and TH2 subsets of CD4 T cells. This was achieved by determining whether MPA and/or NET-A targeted specific subsets of T helper cells by measuring the distinct regulatory cytokines, IFNγ and IL-4. The mechanism and role of the T helper subsets are discussed in the introduction of this chapter. Our results were portrayed as a ratio of TH2: TH1 on which the statistical analysis was done. In addition to the analysis done on the ratio, we analyzed the helper subsets separately in order to determine which subset(s) were influenced. The results of this chapter showed that neither MPA nor NET-A significantly affected either one of the helper subsets, while Dex significantly decreased this ratio. After our observed effects of MPA and NET-A on CD8 T cells, it became of interest in Chapter 5 to investigate the effects of these two synthetic hormones on the CD8 T cell-specific chemokine, RANTES. This was achieved by measuring the effects MPA and NET-A had on RANTES production in vitro by means of ELISA. Surprisingly, we discovered in this chapter that MPA and NET-A enhanced RANTES production before and after activation of CD8 T cells. We also found that Dex had the same effect on RANTES production, but to a lesser degree. Finally, a general conclusion depicting the significance and implications of our results as well as possible future research that is required is presented in Chapter 6. It was of great importance to discuss and interpret the magnitude of data generated out of all our experiments to the utmost of our capabilities. We found that MPA, even at contraceptive doses, displayed significant immunosuppressive as well as anti-inflammatory properties. NET-A, on the other hand, demonstrated weaker immunosuppressive properties in our research and no significant anti-inflammatory properties. These findings could have clinical implications in females being treated with these synthetic contraceptives. We also demonstrated significant variation found amongst genders in response to MPA, NET-A and Dex.
6

"Avaliação do tratamento hormonal e/ou intervencionista por punção nos tumores císticos de ovários" / Evaluation of hormonal treatment and/or intervention through aspiration of ovarian cystic tumors

Chnee, Lúcia Helena 06 September 2006 (has links)
Objetivo: O objetivo deste estudo foi avaliar em mulheres com tumores císticos de ovário, a proporção que, somente com o tratamento clínico e/ou punção, não necessitaram de cirurgia; a influência da medicação e das doenças associadas na indicação de cirurgia e se a punção reduziu significativamente o tamanho dos cistos. Casuística e métodos: Selecionaram-se 71 mulheres com idade entre 19 e 70 anos de idade, portadoras de tumores císticos de ovário maior que 5 cm, com características de benignidade ao ultra-som transvaginal com Doppler colorido e pulsado e com perfil endócrino e marcadores séricos tumorais normais. Foram divididas em cinco grupos: 1) Grupo A: 15 mulheres que fizeram uso de acetato de noretisterona; 2) Grupo B: 13 mulheres que fizeram uso de acetato de medroxiprogesterona; 3) Grupo C: 14 mulheres que utilizaram contraceptivo oral; 4) Grupo D: 15 mulheres que foram tratadas com análogo de GnRH e 5) Grupo E: 14 mulheres que não fizeram uso de medicação. Todos os grupos foram acompanhados por um ano. No final do primeiro trimestre, se o cisto persistiu, foi realizada a punção. No final do segundo trimestre, se houve recidiva do cisto, foi indicada cirurgia. As pacientes tiveram alta após um ano de acompanhamento com o tratamento do cisto concluído. Resultados: Não houve diferenças significantes entre os cinco grupos. Constatou-se que a condição de uso de medicação para doença associada teve influência significativa no resultado dos tratamentos. Verificou-se que a redução do tamanho do cisto com a punção foi efetiva após 9 meses de acompanhamento. Observou-se que 7% das mulheres tiveram indicação direta para cirurgia sem a punção, portanto, a proporção de recidiva da punção foi de 19,3% enquanto a porcentagem de mulheres que não fizeram a cirurgia foi de 73,2%. Conclusão: A proporção de mulheres que responderam adequadamente somente com o tratamento clínico e/ou a punção, não necessitando pois de cirurgia foi de 73,2%. A influência da medicação/ doença associada no tratamento não cirúrgico foi significativa. A redução do tamanho dos cistos benignos em função do tratamento instituído incluindo a punção foi significativa, a qual foi observada após 9 meses de tratamento. / Objectives: To evaluate the rate of women with ovarian cystic tumors submitted to diferent regimens of hormonal treatment and/or aspiration that didn’t need surgery. To access the effectiveness of ovarian cyst aspiration guided by ultrasonography (USG) and to study the influence of medication and associated diseases in the need for surgery. Patients and Methods: Seventy one (71) women, in an age range from 19 to 70 years, diagnosed with ovarian cysts larger than 5 cm in length, with benign aspect, examined using an ultrasonographic transvaginal probe and color Doppler. All the women have been submitted to measurements of ser um tumor markers and hormonal levels. They were grouped in five different categories: 1) Group A: 15 women treated with noretisterone acetate; 2) Group B: 13 subjects treated with medrooxiprogesterone acetate; 3) Group C: 14 patients treated with combined oral contraceptive; 4) Group D: 15 women treated with GnRH analog, and 5) Group E: 15 women with no treatment control). After 3 months, all the patients were reevaluated. In those ones whose cysts remained, cyst aspiration guided by ultrasonography was indicated. After 3 extra months, the women were submitted to a new USG examination and in those whose cysts still remained, surgery was performed. All the patients were followed for one year. Results: There was no significant difference among the groups of hormonal treatment. The use of medication promoted a significant influence in the treatment outcomes. We also noted that the cyst aspiration was effective in reducing the size of the cysts after 9 months of follow up. Seven per cent (7%) of the patients have had immediate indication for surgery. Among those who was submitted to cyst aspiration, 19.3% had to be resubmitted to treatment because of re-incidence of the cyst, whereas, 73.2% avoid the need for surgery. Conclusions: The proportion of subjects treated with hormones and/or cyst aspiration, with no need for surgery, was of 73.2%. The influence of medication/associated disease in the treatments without surgery was significant. The reduction of size of the cysts because of the hormonal and/or aspiration treatment was significant, which was observed after 9 months of therapy.
7

"Avaliação do tratamento hormonal e/ou intervencionista por punção nos tumores císticos de ovários" / Evaluation of hormonal treatment and/or intervention through aspiration of ovarian cystic tumors

Lúcia Helena Chnee 06 September 2006 (has links)
Objetivo: O objetivo deste estudo foi avaliar em mulheres com tumores císticos de ovário, a proporção que, somente com o tratamento clínico e/ou punção, não necessitaram de cirurgia; a influência da medicação e das doenças associadas na indicação de cirurgia e se a punção reduziu significativamente o tamanho dos cistos. Casuística e métodos: Selecionaram-se 71 mulheres com idade entre 19 e 70 anos de idade, portadoras de tumores císticos de ovário maior que 5 cm, com características de benignidade ao ultra-som transvaginal com Doppler colorido e pulsado e com perfil endócrino e marcadores séricos tumorais normais. Foram divididas em cinco grupos: 1) Grupo A: 15 mulheres que fizeram uso de acetato de noretisterona; 2) Grupo B: 13 mulheres que fizeram uso de acetato de medroxiprogesterona; 3) Grupo C: 14 mulheres que utilizaram contraceptivo oral; 4) Grupo D: 15 mulheres que foram tratadas com análogo de GnRH e 5) Grupo E: 14 mulheres que não fizeram uso de medicação. Todos os grupos foram acompanhados por um ano. No final do primeiro trimestre, se o cisto persistiu, foi realizada a punção. No final do segundo trimestre, se houve recidiva do cisto, foi indicada cirurgia. As pacientes tiveram alta após um ano de acompanhamento com o tratamento do cisto concluído. Resultados: Não houve diferenças significantes entre os cinco grupos. Constatou-se que a condição de uso de medicação para doença associada teve influência significativa no resultado dos tratamentos. Verificou-se que a redução do tamanho do cisto com a punção foi efetiva após 9 meses de acompanhamento. Observou-se que 7% das mulheres tiveram indicação direta para cirurgia sem a punção, portanto, a proporção de recidiva da punção foi de 19,3% enquanto a porcentagem de mulheres que não fizeram a cirurgia foi de 73,2%. Conclusão: A proporção de mulheres que responderam adequadamente somente com o tratamento clínico e/ou a punção, não necessitando pois de cirurgia foi de 73,2%. A influência da medicação/ doença associada no tratamento não cirúrgico foi significativa. A redução do tamanho dos cistos benignos em função do tratamento instituído incluindo a punção foi significativa, a qual foi observada após 9 meses de tratamento. / Objectives: To evaluate the rate of women with ovarian cystic tumors submitted to diferent regimens of hormonal treatment and/or aspiration that didn’t need surgery. To access the effectiveness of ovarian cyst aspiration guided by ultrasonography (USG) and to study the influence of medication and associated diseases in the need for surgery. Patients and Methods: Seventy one (71) women, in an age range from 19 to 70 years, diagnosed with ovarian cysts larger than 5 cm in length, with benign aspect, examined using an ultrasonographic transvaginal probe and color Doppler. All the women have been submitted to measurements of ser um tumor markers and hormonal levels. They were grouped in five different categories: 1) Group A: 15 women treated with noretisterone acetate; 2) Group B: 13 subjects treated with medrooxiprogesterone acetate; 3) Group C: 14 patients treated with combined oral contraceptive; 4) Group D: 15 women treated with GnRH analog, and 5) Group E: 15 women with no treatment control). After 3 months, all the patients were reevaluated. In those ones whose cysts remained, cyst aspiration guided by ultrasonography was indicated. After 3 extra months, the women were submitted to a new USG examination and in those whose cysts still remained, surgery was performed. All the patients were followed for one year. Results: There was no significant difference among the groups of hormonal treatment. The use of medication promoted a significant influence in the treatment outcomes. We also noted that the cyst aspiration was effective in reducing the size of the cysts after 9 months of follow up. Seven per cent (7%) of the patients have had immediate indication for surgery. Among those who was submitted to cyst aspiration, 19.3% had to be resubmitted to treatment because of re-incidence of the cyst, whereas, 73.2% avoid the need for surgery. Conclusions: The proportion of subjects treated with hormones and/or cyst aspiration, with no need for surgery, was of 73.2%. The influence of medication/associated disease in the treatments without surgery was significant. The reduction of size of the cysts because of the hormonal and/or aspiration treatment was significant, which was observed after 9 months of therapy.

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