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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.
41

A leptina regula a proliferação celular e a apoptose na próstata humana / The lepitin regulate the celular proliferation and apoptosis in human prostate

Eduardo Moussa de Jabur Leze 22 June 2011 (has links)
A hiperplasia prostática benigna (HPB) é a doença na qual a próstata demonstra um crescimento anormal e sua prevalência aumenta com o envelhecimento. Leptina, a adipocina mais notável, tem um importante papel na regulação do sistema reprodutivo. Esse trabalho tem por fim avaliar o papel da leptina no tecido prostático humano, utilizando a cultura de tecido in vitro, avaliando a proliferação celular e a expressão dos genes do fator de crescimento do fibroblasto 2 (FGF2), da enzima aromatase e dos genes apoptóticos. De 2009 a 2011, amostras de tecido hiperplásico humano foram obtidas pela prostatectomia transvesical em quinze pacientes com próstatas de volume aumentadas. Cada amostra foi dividida em quatro partes simétricas, mantidas no meio RPMI suplementado com soro fetal bovino a 10%, e 1ng/mL de gentamicina, adicionados a 16 ng/mL de leptina (Leptina) ou não (Controle). Após três horas a expressão dos genes de FGF2, aromatase, Bax, Bcl-x e Bcl-2 foram avaliados por RT-PCR em tempo real. A proliferação celular foi avaliada por imunohistoquímica para PCNA. O tratamento com leptina levou a um aumento na expressão de Bax (C=0.40.1; L=0.90.2; p<0.05), enquanto as expressões de Bcl-2 (C=19.95.6; L=5.61.8; p< 0.05) e Bcl-x (C=0.20.06; L=0.070.02; p<0.05) foram significativamente reduzidas. Não houve alteração significativa na expressão de FGF2, enquanto a expressão da aromatase foi significativamente (C=1.90.6; L=0.40.1; p<0.04) reduzida. A leptina também levou a um aumento na proliferação celular (C=21.80.5; L=64.80.9; p<0.0001). Dessa forma, concluímos que a leptina tem um importante papel na manutenção do crescimento fisiológico da próstata, desde que estimula tanto a proliferação celular como a apoptose, com diminuição na expressão do gene da aromatase. / The benign prostate hyperplasia (BPH) is the disease in which the prostate shows an abnormal growth and its prevalence rise up with aging. Leptin, the most well characterized adipokine, has an important role regulating the reproductive system. This paper aimed to evaluate the leptin role in the human prostate tissue, using an in vitro tissue culture system, on the cellular proliferation and the expression of fibroblast growth factor 2, aromatase enzyme and apoptotic genes. From 2009 to 2011, hyperplasic prostate tissue samples obtained by transvesical prostatectomy in fifteen patients with enlarged prostates were used. Each sample was divided in four symmetric parts which were maintained in RPMI medium supplemented with 10% fetal bovine serum, 1 ng/mL of gentamicin and added with 16 ng/mL leptin (L) or not (C). After 3 hours gene expression of FGF2, aromatase, Bax, Bcl-x and Bcl-2 were evaluated by Real Time RT-PCR. Cellular proliferation was evaluated by imunohistochemistry for PCNA. The leptin treatment led to an increase in the expression of Bax (C=0.40.1; L=0.90.2; p<0.05) while Bcl-2 (C=19.95.6; L=5.61.8; p< 0.05) and Bcl-x (C=0.20.06; L=0.070.02; p<0.05) expressions were significantly reduced. There was no significant alteration in the FGF2 expression, while the aromatase expression was significantly (C=1.90.6; L=0.40.1; p<0.04) reduced. Leptin also resulted in an increase in cellular proliferation (C=21.80.5; L=64.80.9; p<0.0001). The conclusion is that leptin has an important role in maintaining the physiological growth of the prostate since it stimulates both cellular proliferation and apoptosis, with the decrement in the aromatase gene expression
42

A leptina regula a proliferação celular e a apoptose na próstata humana / The lepitin regulate the celular proliferation and apoptosis in human prostate

Eduardo Moussa de Jabur Leze 22 June 2011 (has links)
A hiperplasia prostática benigna (HPB) é a doença na qual a próstata demonstra um crescimento anormal e sua prevalência aumenta com o envelhecimento. Leptina, a adipocina mais notável, tem um importante papel na regulação do sistema reprodutivo. Esse trabalho tem por fim avaliar o papel da leptina no tecido prostático humano, utilizando a cultura de tecido in vitro, avaliando a proliferação celular e a expressão dos genes do fator de crescimento do fibroblasto 2 (FGF2), da enzima aromatase e dos genes apoptóticos. De 2009 a 2011, amostras de tecido hiperplásico humano foram obtidas pela prostatectomia transvesical em quinze pacientes com próstatas de volume aumentadas. Cada amostra foi dividida em quatro partes simétricas, mantidas no meio RPMI suplementado com soro fetal bovino a 10%, e 1ng/mL de gentamicina, adicionados a 16 ng/mL de leptina (Leptina) ou não (Controle). Após três horas a expressão dos genes de FGF2, aromatase, Bax, Bcl-x e Bcl-2 foram avaliados por RT-PCR em tempo real. A proliferação celular foi avaliada por imunohistoquímica para PCNA. O tratamento com leptina levou a um aumento na expressão de Bax (C=0.40.1; L=0.90.2; p<0.05), enquanto as expressões de Bcl-2 (C=19.95.6; L=5.61.8; p< 0.05) e Bcl-x (C=0.20.06; L=0.070.02; p<0.05) foram significativamente reduzidas. Não houve alteração significativa na expressão de FGF2, enquanto a expressão da aromatase foi significativamente (C=1.90.6; L=0.40.1; p<0.04) reduzida. A leptina também levou a um aumento na proliferação celular (C=21.80.5; L=64.80.9; p<0.0001). Dessa forma, concluímos que a leptina tem um importante papel na manutenção do crescimento fisiológico da próstata, desde que estimula tanto a proliferação celular como a apoptose, com diminuição na expressão do gene da aromatase. / The benign prostate hyperplasia (BPH) is the disease in which the prostate shows an abnormal growth and its prevalence rise up with aging. Leptin, the most well characterized adipokine, has an important role regulating the reproductive system. This paper aimed to evaluate the leptin role in the human prostate tissue, using an in vitro tissue culture system, on the cellular proliferation and the expression of fibroblast growth factor 2, aromatase enzyme and apoptotic genes. From 2009 to 2011, hyperplasic prostate tissue samples obtained by transvesical prostatectomy in fifteen patients with enlarged prostates were used. Each sample was divided in four symmetric parts which were maintained in RPMI medium supplemented with 10% fetal bovine serum, 1 ng/mL of gentamicin and added with 16 ng/mL leptin (L) or not (C). After 3 hours gene expression of FGF2, aromatase, Bax, Bcl-x and Bcl-2 were evaluated by Real Time RT-PCR. Cellular proliferation was evaluated by imunohistochemistry for PCNA. The leptin treatment led to an increase in the expression of Bax (C=0.40.1; L=0.90.2; p<0.05) while Bcl-2 (C=19.95.6; L=5.61.8; p< 0.05) and Bcl-x (C=0.20.06; L=0.070.02; p<0.05) expressions were significantly reduced. There was no significant alteration in the FGF2 expression, while the aromatase expression was significantly (C=1.90.6; L=0.40.1; p<0.04) reduced. Leptin also resulted in an increase in cellular proliferation (C=21.80.5; L=64.80.9; p<0.0001). The conclusion is that leptin has an important role in maintaining the physiological growth of the prostate since it stimulates both cellular proliferation and apoptosis, with the decrement in the aromatase gene expression
43

Untersuchungen der lokalen Östrogenbiosynthese in Knorpelgewebe und chrondrogenen Progenitorzellen in späten Stadien der Arthrose / Investigations of local estrogen biosynthesis in cartilage and chondrogenic progenitor cells in late stages of osteoarthritis

Reinermann, Marcus 13 April 2016 (has links)
No description available.
44

Role for oestrogen in dynamic interactions between cell types within the human endometrium

Gibson, Douglas Alistair January 2012 (has links)
The human endometrium is a complex multicellular tissue, located within the cavity of the uterus. Its luminal surface is defined by a layer of epithelial cells supported on a multicellular stroma containing fibroblasts, glands (lined by a secretory epithelium), blood vessels (lined with endothelial cells) and several populations of immune cells; the latter includes a unique population of natural killer (uNK) cells. The endometrium undergoes dynamic remodelling across the menstrual cycle in response to fluctuating levels of sex steroids secreted by ovarian cells. The phases of the endometrial cycle include an oestrogendominated proliferative phase, a progesterone-dominated secretory phase and menses (endometrial shedding precipitated by falling levels of progesterone). A key feature of the secretory phase is differentiation (decidualisation) of endometrial stromal fibroblasts (ESC) an event characterised by transformation of cell shape, secretion of growth factors/cytokines, angiogenesis/vascular remodelling and an increase in the numbers of resident immune cells. Decidualisation ensures an appropriate nutritional and hormonal environment exists during the establishment of pregnancy. Studies in mice suggest that de novo biosynthesis of oestrogen within the uterus may play an essential role in regulation of decidualisation but no data exist for human. Endometrial endothelial and uNK cells both contain oestrogen receptors but the impact of oestrogens on their function has not been explored. In the current studies three questions have been addressed: 1. Is oestrogen biosynthesis a feature of human endometrial stromal cell decidualisation? 2. What is the impact of oestrogen on uNK cell function? 3. What role (if any) does oestrogen play in the interplay between decidual, immune and vascular cells within the human endometrial stroma? Results obtained provide the first evidence that de novo biosynthesis of oestrogens occurs during decidualisation of human ESC. This was attributed to changes in expression patterns of mRNAs encoding proteins that play a critical role in regulation of oestrogen biosynthesis (STAR, CYP11A1, CYP19A1 [aromatase], HSD17B2 [17βHSD2] and STS [steroid sulphatase]). Changes in the pattern of metabolism were confirmed using thin layer chromatography and analysis of concentrations of oestrone (E1) and oestradiol (E2) in culture media. Secretion of E1 and E2 was reduced by addition of an aromatase inhibitor. Data derived from studies described within this thesis also show for the first time that incubation of uNK cells with E2 not only enhanced cell migration but also stimulated secretion of factors that had a significant impact on endothelial cell angiogenesis. These findings were supported by novel evidence that E2 had a significant impact on expression of genes associated with cell motility and angiogenesis. In addition, factors, including E1/E2, secreted by decidualised stromal cells, stimulated chemotaxis of uNK cells. Future experiments will focus on determining the identity of the angiogenic factors secreted by uNK cells in response to E2 and the mechanisms responsible for uNK cell movement. In summary, new data presented in this thesis provide evidence that local biosynthesis of oestrogens within the endometrial stroma may play a previously unrecognised role in regulating the function of uNK cells and endometrial endothelial cells in women. These results have implications for treatment of disorders such as infertility, heavy menstrual bleeding and endometriosis.
45

The reproductive phenotype of the male aromatase knockout mouse

Robertson, Kirsten, 1975- January 2001 (has links)
Abstract not available
46

Modulation of Intracrine Estrogen in Menopausal Women: Implications for Women’s Reproductive Health and Breast Cancer Risk

Mousa, Noha 17 February 2011 (has links)
Extensive research and clinical observations in the past 20 years confirmed that the cessation of ovarian function at menopause does not stop the process of sex steroid hormone synthesis in females. Indeed, multiple extra-ovarian tissues contain the same enzymatic machinery the ovary uses which can maintain a significant rate of local hormonal synthesis sufficient to cause pathological outcomes. This is commonly termed “intracrine”. However, two obstacles face intracrinology. Firstly, wide clinical appreciation of this mechanism in causing disease and in targeting it with therapy does not currently exist. Secondly, blood hormonal assays are used in the clinic to diagnose and manage intracrine based disorders. This could be entirely misleading, since hormonal synthesis, action and metabolism occur within the tissue and, therefore, measuring blood levels is not reflective of the actual disease environment. This thesis presents evidence of significant intracrine based disorders in menopausal women that could be effectively managed by tackling the core intracrine mechanism. Three protocols are investigated emphasizing the usefulness of menopausal intracrine estrogen inhibition. The first presents a joint objective of treating menopausal symptoms using estrogenic replacement therapy while reducing breast cancer risk using long-term aromatase inhibitors. Aromatase inhibition is used to suppress the local estrogen synthesis in the breast. The second protocol is a new method of acute inhibition of breast estrogens to improve the accuracy of breast imaging techniques. This method showed a benefit in reducing the benign parenchymal enhancement during breast MRI indicating a potential improvement in specificity. The third protocol involves using aromatase inhibitors in the treatment of severe endometriosis that did not respond to oophorectomy. The pathogenesis of breast cancer, endometriosis and fibroids are believed to involve intracrine estrogen activity. Another significant contribution presented in this thesis is the development of a new technique that enables minimally invasive tissue assays of hormones in their genuine site of synthesis rather than indirectly in the blood. The new assay requires only microliter volumes of sample and employs a novel digital microfluidics technology. Estrogen and other sex steroids were extracted from droplet-scale breast tissue and blood samples.
47

Effects of a non-steroidal aromatase inhibitor on ovarian function in cattle

Yapura, Jimena 15 September 2009
Two studies were designed to characterize the effects of a non-steroidal aromatase inhibitor, letrozole, on ovarian function in cattle. The specific objective was to test the hypothesis that letrozole will arrest dominant follicle growth resulting in emergence of a new follicular wave at a predictable interval post-treatment. In a first experiment, postpubertal beef heifers were assigned randomly to four treatment groups and given phosphate-buffered saline (controls; n=10), or letrozole at a dose of 500 (n=9), 250 (n=10), or 125 (n=10) µg/kg intravenously 4 days after follicular ablation (~2.5 days after wave emergence). In a second study, postpubertal beef heifers were assigned randomly to four treatment groups. One group received no treatment (control; n=17) and the other groups (n=9-10) were given 85 µg/kg of letrozole per day (250 µg/kg total dose), from Days 1 to 3, Days 3 to 5, or Days 5 to 7 (Day 0 = pre-treatment ovulation,) corresponding to the periods before, during and after selection of the dominant follicle, respectively. Follicular dynamics were monitored ultrasonically and blood samples were collected for endocrine assays. Follicle diameter profiles and plasma LH, FSH, and estradiol concentrations were analyzed. Additionally, during the second trial, CL diameter profiles and plasma progesterone concentrations were measured. In both studies, the diameter profile of the dominant follicle was larger in heifers treated with letrozole than in control heifers (P<0.05) and the intervals to new wave emergence and onset of regression of the extant dominant follicle were longer (P<0.05) in heifers treated with letrozole than in controls, regardless of the dose (high, medium, or low; single vs multiple) and the stage of the follicle wave in which treatments were initiated. Furthermore, during the second experiment, the mean CL diameter was larger in letrozole-treated heifers, although there were no differences in plasma progesterone concentrations between treated and control animals. The effects on dominant follicle and CL diameter profiles appeared to be the result of the significantly increased plasma LH concentrations observed in letrozole-treated animals during both treatment approaches (single vs multiple dose). Incomplete and inconsistent inhibition of estradiol production and the lack of a surge on FSH observed in both experiments may be a result of insufficient circulating levels of letrozole during the treatment period. In summary, a single or multiple dose of letrozole did not induce regression of the extant dominant follicle, nor did it directly affect FSH release. Conversely, letrozole extended the lifespan of the dominant follicle, in association with increased endogenous levels of LH, thereby delaying the next FSH surge and subsequent follicular wave emergence. Results suggest that letrozole has potential as a non-steroidal method for controlling ovarian function in cattle, but further studies are warranted to clarify dosage and timing of treatment to predictably affect follicular wave dynamics in cattle.
48

Modulation of Intracrine Estrogen in Menopausal Women: Implications for Women’s Reproductive Health and Breast Cancer Risk

Mousa, Noha 17 February 2011 (has links)
Extensive research and clinical observations in the past 20 years confirmed that the cessation of ovarian function at menopause does not stop the process of sex steroid hormone synthesis in females. Indeed, multiple extra-ovarian tissues contain the same enzymatic machinery the ovary uses which can maintain a significant rate of local hormonal synthesis sufficient to cause pathological outcomes. This is commonly termed “intracrine”. However, two obstacles face intracrinology. Firstly, wide clinical appreciation of this mechanism in causing disease and in targeting it with therapy does not currently exist. Secondly, blood hormonal assays are used in the clinic to diagnose and manage intracrine based disorders. This could be entirely misleading, since hormonal synthesis, action and metabolism occur within the tissue and, therefore, measuring blood levels is not reflective of the actual disease environment. This thesis presents evidence of significant intracrine based disorders in menopausal women that could be effectively managed by tackling the core intracrine mechanism. Three protocols are investigated emphasizing the usefulness of menopausal intracrine estrogen inhibition. The first presents a joint objective of treating menopausal symptoms using estrogenic replacement therapy while reducing breast cancer risk using long-term aromatase inhibitors. Aromatase inhibition is used to suppress the local estrogen synthesis in the breast. The second protocol is a new method of acute inhibition of breast estrogens to improve the accuracy of breast imaging techniques. This method showed a benefit in reducing the benign parenchymal enhancement during breast MRI indicating a potential improvement in specificity. The third protocol involves using aromatase inhibitors in the treatment of severe endometriosis that did not respond to oophorectomy. The pathogenesis of breast cancer, endometriosis and fibroids are believed to involve intracrine estrogen activity. Another significant contribution presented in this thesis is the development of a new technique that enables minimally invasive tissue assays of hormones in their genuine site of synthesis rather than indirectly in the blood. The new assay requires only microliter volumes of sample and employs a novel digital microfluidics technology. Estrogen and other sex steroids were extracted from droplet-scale breast tissue and blood samples.
49

Effects of a non-steroidal aromatase inhibitor on ovarian function in cattle

Yapura, Jimena 15 September 2009 (has links)
Two studies were designed to characterize the effects of a non-steroidal aromatase inhibitor, letrozole, on ovarian function in cattle. The specific objective was to test the hypothesis that letrozole will arrest dominant follicle growth resulting in emergence of a new follicular wave at a predictable interval post-treatment. In a first experiment, postpubertal beef heifers were assigned randomly to four treatment groups and given phosphate-buffered saline (controls; n=10), or letrozole at a dose of 500 (n=9), 250 (n=10), or 125 (n=10) µg/kg intravenously 4 days after follicular ablation (~2.5 days after wave emergence). In a second study, postpubertal beef heifers were assigned randomly to four treatment groups. One group received no treatment (control; n=17) and the other groups (n=9-10) were given 85 µg/kg of letrozole per day (250 µg/kg total dose), from Days 1 to 3, Days 3 to 5, or Days 5 to 7 (Day 0 = pre-treatment ovulation,) corresponding to the periods before, during and after selection of the dominant follicle, respectively. Follicular dynamics were monitored ultrasonically and blood samples were collected for endocrine assays. Follicle diameter profiles and plasma LH, FSH, and estradiol concentrations were analyzed. Additionally, during the second trial, CL diameter profiles and plasma progesterone concentrations were measured. In both studies, the diameter profile of the dominant follicle was larger in heifers treated with letrozole than in control heifers (P<0.05) and the intervals to new wave emergence and onset of regression of the extant dominant follicle were longer (P<0.05) in heifers treated with letrozole than in controls, regardless of the dose (high, medium, or low; single vs multiple) and the stage of the follicle wave in which treatments were initiated. Furthermore, during the second experiment, the mean CL diameter was larger in letrozole-treated heifers, although there were no differences in plasma progesterone concentrations between treated and control animals. The effects on dominant follicle and CL diameter profiles appeared to be the result of the significantly increased plasma LH concentrations observed in letrozole-treated animals during both treatment approaches (single vs multiple dose). Incomplete and inconsistent inhibition of estradiol production and the lack of a surge on FSH observed in both experiments may be a result of insufficient circulating levels of letrozole during the treatment period. In summary, a single or multiple dose of letrozole did not induce regression of the extant dominant follicle, nor did it directly affect FSH release. Conversely, letrozole extended the lifespan of the dominant follicle, in association with increased endogenous levels of LH, thereby delaying the next FSH surge and subsequent follicular wave emergence. Results suggest that letrozole has potential as a non-steroidal method for controlling ovarian function in cattle, but further studies are warranted to clarify dosage and timing of treatment to predictably affect follicular wave dynamics in cattle.
50

Aromatazės slopinimo embriogenezėje poveikis suaugusių naminių vištų patelių elgsenos struktūrai / Aromatare suppression effect for the domestic han females behaviour structure

Konovalova, Nadežda 08 September 2009 (has links)
Pastaraisiais metais vyksta labai daug elgsenos endokrininės kontrolės tyrimų. Mūsų darbe mes tyrėme galimą estrogenų vaidmenį vištų patelių lytinės elgsenos difirenciacijai. Eksperimentiniai gyvūnai 8 embrioninio vystymosi dieną buvo aveikti aromatazės inhibitoriumi, fadrozoliu, tokiu būdu blokuojant estradiolio gamybą. Kontroliniams gyvūnams buvo suleistas fizioliginis tirpalas. Suaugusių vištų elgsena buvo stebima dvejuose skirtinguose lytinės elgsenos testuose: su suaugusiu intaktiniu (nepaveiktu) gaidžiu ir su intaktine (kontroline) višta. Testuojant su gaidžiu fadrozoliu paveiktos vištos rodė mažesnį pasiruošimą kopuliuoti su gaidžiu, turėjo polinkį dominuoti ir vengti gaidį. Testuojant su kontroline višta, eksperimentiniai paukščiai rodė vyrišką elgseną - sparno rėžimą, bandymus kopuliuoti ir giedojimą. Kelios fadrozoliu paveiktos vištos rodė pilną kopuliacinės elgsenos seką, tame tarpe kloakų kontakto judesius. Mūsų tyrimai palaiko hipotezę, kad estrogenai yra pagrindinis faktorius, lemiantis naminių vištų lytinės elgsenos diferenciaciją. / In recent years much scientific reseach is devoted to the endocrine control of behaviour. In our work we studied the possible role of estrogens in differentiation of sexual behaviour in female chickens. Eksperimental animals were treated on day 8 of embrionic development with an aromataze inhibitor, fadrozole, thus blocking the oestradiol production. Control animals received injections of vehicle (saline). In adulthood behaviour of hens was observed in two different sexual behaviour tests: with mature non-treated (intact) cocks and with non-treated (control) hens. When tested with a cock, fadrozole-treated hens showed reduced readiness to copulate with a cock, tended to dominate and to avoid a cock. When tested with a control hen, experimental birds displayed male-type behaviour – waltzing, mount attempts and crowing,. Some of fadrozole-treated hens showed a full sequence of copulatory behaviour, including cloacal contact movement. Our study supports the hypothesis that oestrogens play a major role in differentiation of sexual behaviour in the domestic chickens.

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