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In Vitro Studies of Adrenocorticolytic DDT Metabolites, with Special Focus on 3-methylsulfonyl-DDEAsp, Vendela January 2010 (has links)
The DDT metabolite 3-methylsulfonyl-DDE (3-MeSO2-DDE) is bioactivated by cytochrome P450 11B1 (CYP11B1) in the adrenal cortex of mice and forms irreversibly bound protein adducts, reduces glucocorticoid secretion, and induces cell death selectively in cortisol-producing adrenocortical cells. 3-MeSO2-DDE has therefore been proposed as a lead compound for an improved adrenocortical carcinoma (ACC) therapy. The aims of this thesis were to (1) develop in vitro test systems based on murine and human adrenocortical cell lines and to (2) investigate the mechanisms behind 3-MeSO2-DDE toxicity in adrenocortical cells. The cytotoxic and endocrine-modulating effects of 3-MeSO2-DDE were compared to those of o,p′-DDD (mitotane), the current ACC therapy, and to those of several structurally analogous compounds in both murine and human cell lines. 3-MeSO2-DDE bioactivation and cytotoxicity proceeded in a similar manner in the murine adrenocortical Y-1 cell line as in mice in vivo. The effects were highly structure-specific. Moreover, 3-MeSO2-DDE formed irreversibly bound protein adducts and caused cell death also in the human H295R cell line, and was slightly more cytotoxic than o,p′-DDD. However, 3-MeSO2-DDE toxicity in human cells was not affected by the CYP11B1 inhibitor etomidate, suggesting that bioactivation in human cells is performed by additional/other enzyme(s) than CYP11B1. 3-MeSO2-DDE generated biphasic responses in cortisol and aldosterone secretion and in expression levels of the steroidogenic genes CYP11B1, CYP11B2, and StAR. Such hormesis-like responses were not seen for o,p′-DDD or the precursor DDT metabolite p,p′-DDE. In addition, the two o,p′-DDD enantiomers (R)-(+)-o,p′-DDD and (S)-(-)-o,p′-DDD exhibited slight differences in cytotoxic and endocrine-modulating activity in H295R cells. In conclusion, this thesis provides extended knowledge on the mechanisms of action of 3-MeSO2-DDE and points out important differences in effects between murine and human cells. Lead optimisation studies of 3-MeSO2-DDE using the herein presented in vitro test systems are ongoing.
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Prognostic factors for squamous cell cervical cancer : tumor markers, hormones, smoking, and S-phase fractionLindström, Annika January 2010 (has links)
Cervical cancer is the second most common malignancy in women worldwide and one of the leading causes of cancer mortality globally. In patients with invasive cervical cancer prognostic factors are of value for the choice of treatment, monitoring of treatment and follow-up. The most important clinical prognostic factors are stage, tumor volume, parametrial infiltration, vascular invasion, lymph node metastases, and distant metastases. An improved estimation of the prognosis of cervical cancer is desirable, especially in early cancer stages. The aim of this research was to study possible associations between tumor markers, female sex steroids, smoking, S-phase fraction (SPF), and prognosis in invasive squamous cell cervical cancer (SCC). The study comprised 190 patients with SCC, stages IB-IV, admitted to the Department of Gynecologic Oncology at Norrland University Hospital in Umeå between September 1984 and October1990. Ten year mortality was estimated. In study I, of a total of 103 patients, it was found that increased tumor growth, measured by the DNA SPF, was associated with elevated serum progesterone and smoking in the premenopasual patients and with aneuploidy in the whole group. In study II, comprising 128 patients, survival length related to hormone levels and SPF was evaluated in women who died of cervical cancer. In both pre- and postmenopausal women, who died of cervical cancer, SPF at or above 12% was correlated with reduced survival. There was significant positive correlation between a low serum estradiol/progesterone ratio and short survival in those premenopausal women who died of cancer (p=0.02). In study III, ten-year follow-up results in 128 women were compared with the expression of ten relevant tumor markers, assessed by immunohistochemistry. The overall ten-year survival rate in patients with low COX-2 and high CD4+ expression was 76%, versus 53% in the remaining women. The survival rate with absent p53 and high COX-2 expression in the tumors was 42%, versus 71%, while the corresponding figure for the combination of high COX-2 intensity and expression of c-myc was 27%, versus 62%. None of the single markers correlated significantly with outcome in the final Cox regression analyses, while five combinations did. Study IV addressed possible associations between selected tumor markers and cofactors in SCC. Ten tumor markers were examined in 128 patients. Smoking habits and previous oral contraceptive use were recorded. Serum estradiol and progesterone levels were evaluated in 80 women. Highly significant associations were found between strong c-myc staining and increased progesterone, low EGFR staining and high serum estradiol, and absence of p53 staining and smoking. There was an association between absence of p53 and high serum progesterone. In study V, LRIG1 expression was studied in 128 patients and was compared with expression of nine other tumor markers, smoking history, hormone levels, and prognosis. LRIG1 appears to be a significant prognostic predictor in early stage SCC, independent of the other tumor markers that were studied. Diminished expression in advanced cancer stages and the inverse correlation to serum progesterone and smoking indicate that LRIG1 is a tumor suppressor in squamous cell cervical cancer. Conclusion: The results of these studies support a role of progesterone as a promoter of cervical cancer and indicate that smoking is associated with tumor progression. A combination of tumor markers might be of help in prognostic prediction. LRIG1 acts as a tumor suppressor. These findings might contribute towards greater understanding of prognostic prediction of squamous cell cervical cancer.
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Characterization of the role of acid ceramidase in adrenocortical steroid hormone biosynthesisLucki, Natasha Chrystman 14 November 2011 (has links)
Sphingolipids modulate multiple cellular functions, including steroid hormone biosynthesis. Sphingosine is an antagonist ligand for the nuclear receptor steroidogenic factor 1 (SF-1), which is the primary transcriptional regulator of most steroidogenic genes. Furthermore, sphingosine-dependent repression of SF-1 function is dependent on the expression of acid ceramidase (ASAH1), an enzyme that forms sphingosine. Based on these data, I hypothesized that ACTH/cAMP signaling regulates ASAH1 function at both transcriptional and post-transcriptional levels. In addition, because SF-1 is predominantly a nuclear protein, I postulated that ASAH1 modulates SF-1 function and, therefore, steroidogenic gene expression by controlling the nuclear concentrations of SPH. To test these hypotheses, I first examined the effect of chronic ACTH/cAMP signaling on the transcription of the ASAH1 gene. Next, the functional significance of ASAH1 expression in adrenocortical cells was probed by generating an ASAH1-knockdown cell line. I subsequently characterized the role of ASAH1 as a transcriptional nuclear receptor coregulator. Finally, I defined the role of sphingosine-1-phosphate, a bi-product of ASAH1 activity, in the acute phase of cortisol biosynthesis. Using a variety of experimental approaches, I identified cAMP response element binding protein as an essential transcriptional activator of the ASAH1 gene. Analysis of adrenocortical cells lacking ASAH1 revealed that ASAH1 is a global regulator of steroidogenic capacity. Furthermore, I identified ASAH1 as a nuclear protein and defined the molecular determinants of the interaction between ASAH1 and SF-1. Collectively, this body of work establishes the integral role of ASAH1 in the regulation of ACTH-dependent adrenocortical cortisol biosynthesis.
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Untersuchungen zur uterinen Expression von Choriongonadotropin und Relaxin sowie weiteren gewebemodulierenden Faktoren im Implantationszeitraum bei Weißbüschelaffen (Callithrix jacchus)Ebert, Katja 25 November 2013 (has links) (PDF)
Die Implantation einer Blastozyste im Uterus stellt für den maternalen Organismus eine große Herausforderung dar. Neben morphologischen Veränderungen des Endometriums sind Anpassungen auch im Immun- und Gefäßsystem notwendig. Kenntnisse über die verantwortlichen Faktoren für diese Prozesse sind bei Menschen und anderen Primaten noch immer unvollständig. Dabei sind Implantationsstörungen oftmals Ursache von Fruchtbarkeitsproblemen (SHARKEY und SMITH 2003). Besonders im Bereich der assistierten Reproduktion stellen implantationsbedingte Probleme eine Hauptursache für geringe Erfolgsraten dar (APLIN und KIMBER 2004). Das Ziel der Erforschung von Mechanismen im Zusammenhang mit der Implantation ist es, ein besseres Verständnis für die physiologischen und auch pathologischen Vorgänge zu erlangen. In dessen Folge die Erkenntnisse für die Behandlung von Implantationsstörungen genutzt werden könnten. Anhand des in der reproduktionsbiologischen Forschung etablierten Primatenmodells des Weißbüschelaffen (Callithrix jacchus) wurde in der vorliegenden Arbeit die Expression ausgewählter Faktoren in verschiedenen Zyklusphasen mit dem Schwerpunkt der Implantationsphase untersucht. Dafür wurden zeitlich genau terminierte Uterusproben von konzeptiven und nicht-konzeptiven Tieren entnommen und molekularbiologisch, histologisch und immunhistochemisch analysiert. Erstmals konnte im Uterus von Weißbüschelaffen die zeitliche und räumliche Regulierung von Choriongonadotropin (CG), Östradiolrezeptor-α (ERα), Östradiolrezeptor-ß (ERß), Progesteronrezeptor (PR), Aromatase (ARO), 17β-Hydroxysterois-Dehydrogenase Typ 7 (17β-HSD7) sowie Relaxin (RLN) und Relaxinrezeptor (RXFP1) auf Gen- und Proteinebene in verschiedenen Zyklusphasen in der vorliegenden Vollständigkeit dargestellt werden. Alle in dieser Arbeit untersuchten Faktoren zeigten eine rezeptorspezifische Veränderung der Expressionsmuster, auf räumlicher und zeitlicher Ebene im Verlauf des Implantationsprozesses. Es konnte dargestellt werden, dass die feto-maternale Kommunikation bereits vor dem direkten Kontakt der Blastozyste mit dem Endometrium beginnt. So wurde bei konzeptiven Tieren eine verstärkte Expression von CG, ERα, PR, 17β-HSD7 und RXFP1 in der Implantationsphase nachgewiesen. Diese Faktoren sind geeignete Kandidaten für weiterführende Untersuchungen und Evaluierung von Markern für die Präimplantationsphase und rezeptiven Uteri von Weißbüschelaffen. Die ebenfalls untersuchten Faktoren ERβ, ARO und RLN zeigten Expressionsmuster, welche erst nach der Implantation bei konzeptiven Tieren Unterschiede aufwiesen. Aus diesem Grund sind diese Faktoren nicht als frühe Marker der Implantationsphase geeignet, gleichwohl sie wichtige Funktionen in der Postimplantationsphase übernehmen.
Die Ergebnisse dieser Arbeit verdeutlichen, dass nicht alleine ein einzelner Faktor eine herausragende Bedeutung im Implantationsprozess hat, sondern vielmehr ein äußerst komplexes Netzwerk von Signalen nötig ist, um eine erfolgreiche Gravidität zu gewährleisten. Die Aufgabe der Steroidrezeptoren ERα und PR liegt in der grundlegenden Bereitstellung eines rezeptiven Uterus während des Implantationszeitfensters. Gleichzeitig erfolgt eine sehr genau koordinierte Regulation dieser Steroidrezeptoren über die lokal produzierten Faktoren CG, ARO, 17β-HSD7, RLN und der Rezeptoren RXFP1 und ERβ. Neben den morphologischen Veränderungen des Endometriums, sind einzelne Faktoren auch bei der Angiogenese und Entwicklung der maternalen Immuntoleranz beteiligt. Es kann demnach davon ausgegangen werden, dass die präzise Regulation dieser Faktoren eine essentielle Voraussetzung für den Erfolg der Implantation und Gravidität ist.
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On the role of the carbohydrate vs the lipid moieties in neoglycolipid self-organisation : Synthesis and liquid crystalline properties of two new families of carbohydrate-based amphiphilesXu, Rui 28 February 2013 (has links) (PDF)
In this study, we have synthesized two families of new carbohydrate-based amphiphilic derivatives: a series of alkyl glucoside ethers varying in terms of chain length and position on the sugar, and a series of glucosteroids varying in terms of alkyl spacer and, for the disutibstuted systems, in terms of alkyl side chain length. By the means of analytical methods, such as NMR spectroscopy, mass spectroscopy and elementary analysis, the structure of all the compounds was carefully established, as well as their purity. Their liquid crystalline behaviors were studied by the means of transmission light microscopy and differential scanning calorimetry. The two families of compounds which have been studied illustrate how much the behavior can be essentially related to polar interactions (H-bonding), therefore to the sugar moiety, for the ether series, or to hydrophobic interactions (lipid-lipid) in the glucosteroid series. In this latter series, preference for either steroid-stroid or steroid alkyl packing appears as an insight in understanding the behavior of complex lipids, showing potentially more than one conformational structure with important consequences on the supramolecular level, therefore to their potential biological role. This could be regarded as "lipid denaturation" by analogy to the protein denaturation. Also, when we see that compounds like the glycosteroids having an long chain ester -CAG, BbGL-I, are found to exist in Nature, and how much glycolipid-cholesterol interactions were recently shown to be critical in some biological processes, it is hoped that our observations can provide a new vision angle for the study of complex lipids and glycolipids. As a start to develop new probes targeting the "lipid raft" microdomain in membranes, we also explored a sequence towards carbohydrate laurdan hybrids. Further development of this strategy and evaluation of the biological properties is programmed within new collaborative projects.
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Steroid-dependent regulation of the oviduct: A cross-species transcriptomal analysisCerny, Katheryn L. 01 January 2015 (has links)
Reproductive success depends on a functional oviduct for gamete storage, maturation, fertilization, and early-conceptus development. The ovarian-derived sex steroids estradiol and progesterone are known to affect functionality of the oviduct. Advances in microarray and NanoString technology allow for gene expression analysis to increase understanding of processes critical for fertility. Studies were conducted to investigate mechanisms regulating oviductal function in cattle and mice by using the Bovine Gene 1.0 ST array and the Mouse Gene 430-2.0 arrays (Affymetrix Inc., CA), respectively.
For the first study, oviducts were collected from heifers assigned to luteal or follicular phase groups. In the second study oviducts were collected from immature mice with a global deletion of estrogen receptor-1 (ESR1) and their wild-type littermates at 23 days of age or 48 hr after treatment with 5 IU of PMSG. Following microarray hybridization, the resulting datasets were analyzed using Partek Genomics Suite 6.6 (Partek Inc., MO).
The results of the first two studies illustrated a dynamic hormonal regulation of the oviductal epithelium and revealed the identity of novel genes affecting fertility in cattle and gave us insights into the genes regulated by estrogen and ESR1 in mice. Many genes identified as differentially regulated are believed to play an integral role in the regulation of oviductal inflammation. Therefore, the objective of the third study was to test the hypothesis that intraperitoneal administration of E. Coli-derived lipopolysaccharide induces the expression of inflammatory mRNAs in the mouse oviduct. Mice were treated with 0, 2 μg or 10 μg of LPS from E. Coli. and killed 24 h later.
Oviducts were collected for determination of inflammatory gene expression by a targeted NanoString approach using the nCounter GX Mouse Inflammation Kit (NanoString Technologies, Wa). Results indicate that systemic treatment with LPS induces inflammation in the oviducts of mice and provides evidence of a repeatable animal model of oviductal inflammation. Overall, data from these studies extends our knowledge of the mechanisms regulating oviductal functions and immune response, as well as identified target molecules and processes to improve production animal and human fertility.
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The Modulation of Androgen Signaling by Steroid Hormones and Mechanical Tension: A Novel Pathway of Labor InitiationLi, Yunqing 14 December 2011 (has links)
We investigated the gestational expression of androgen receptor (AR) and defined its
regulation and that of its co-repressors, PSF and p54nrb, by steroid hormones and
myometrial stretch in vivo in pregnant and non-pregnant rats. Our data demonstrate
that, 1) myometrial AR expression decreases prior to term; 2) AR expression is
up-regulated by MPA treatment and down-regulated by mechanical stretch; (3)
myometrial PSF protein expression is down-regulated by estrogen signaling and by
mechanical stretch, and up-regulated by androgen signaling; (4) while myometrial PSF
mRNA expression is also down-regulated by stretch, the regulation by estrogen and P4
on PSF mRNA appear to be opposite to the effects on PSF protein. We conclude that
the decreased androgen signaling in late pregnancy (as a result of decreased AR and
PSF expression mediated by hormonal and mechanical signals) may contribute to the
mechanisms leading to labor initiation.
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The Modulation of Androgen Signaling by Steroid Hormones and Mechanical Tension: A Novel Pathway of Labor InitiationLi, Yunqing 14 December 2011 (has links)
We investigated the gestational expression of androgen receptor (AR) and defined its
regulation and that of its co-repressors, PSF and p54nrb, by steroid hormones and
myometrial stretch in vivo in pregnant and non-pregnant rats. Our data demonstrate
that, 1) myometrial AR expression decreases prior to term; 2) AR expression is
up-regulated by MPA treatment and down-regulated by mechanical stretch; (3)
myometrial PSF protein expression is down-regulated by estrogen signaling and by
mechanical stretch, and up-regulated by androgen signaling; (4) while myometrial PSF
mRNA expression is also down-regulated by stretch, the regulation by estrogen and P4
on PSF mRNA appear to be opposite to the effects on PSF protein. We conclude that
the decreased androgen signaling in late pregnancy (as a result of decreased AR and
PSF expression mediated by hormonal and mechanical signals) may contribute to the
mechanisms leading to labor initiation.
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Androgenic and oestrogenic effects on the endrocrinology of reproductive development in male and female sheep (Ovis aries L.) / by Christakis Papachristoforou.Papachristoforou, Christakis January 1988 (has links)
Typescript. / "April 1987." / Includes bibliograpical references (leaves 160-194). / xii, 194 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Presents direct comparative information on growth and endocrinological aspects of reproductive development in intact and gonadectomized male and female Merino lambs born in autumn and treated prepubertally with either a non-aromatizable androgen (trenbolone acetate) with higher androgenic potency than testosterone, oestradiol -17beta(oestradiol), or a combination of these two steroid hormones. / Thesis (Ph.D.)--University of Adelaide, Dept. of Animal Sciences, 1988
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Reproductive history and sex hormones and their association with subclinical atherosclerosis in women with and without type 1 diabetes /Snell-Bergeon, Janet K. January 2007 (has links)
Thesis (Ph.D. in Epidemiology) -- University of Colorado Denver, 2007. / Typescript. Includes bibliographical references (leaves 100-117). Free to UCD affiliates. Online version available via ProQuest Digital Dissertations;
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