Atrial natriuretic factor (ANF) is a smooth muscle relaxant. This thesis examined the effects of ANF on rat uterus. ANF inhibited the motor activity of non-gravid but not of the gravid uterus. This decrease in the tocolytic effects of ANF during pregnancy correlated with an increase in plasma progesterone. The tocolytic activity of ANF was also inhibited by exogenous progesterone. In contrast, the sensitivity of the uterus of both virgin and pregnant rats was significantly increased by the progesterone receptor antagonist, RU486. The inhibition of the tocolytic activity of ANF by ovariectomy was reversed by estrogen. Refractoriness to the tocolytic activity of ANF was accompanied by decreases in myometrial ANF receptors and in the stimulant effects of ANF on myometrial particulate guanylate cyclase activity and cyclic guanosine 3$ sp prime$:5$ sp prime$-monophosphate. In contrast, estrogen and RU486 increased myometrial ANF receptors. It is concluded that the exposure of the myometrium to progesterone during pregnancy results in the down-regulation of myometrial ANF receptors, and in turn in a decrease in its tocolytic and biochemical effects on the uterus; this may be physiologically important for the progression of pregnancy and parturition.

Estradienolone (ED, 17beta-hydroxy-[1,5]-estradien-3-one) is a novel steroid hormone identified in pregnant women. It is an isomer of estradiol which binds the progesterone receptor and sex hormone binding globulin with high affinity. Since levels of ED remain high throughout pregnancy and decrease in association with term or preterm labour, ED may be involved in the maintenance of pregnancy. The objectives of the present study were to, (i) purify ED from pregnancy samples in quantities sufficient for chemical analysis to confirm its structural features, and (ii) identify its binding proteins and receptors. Our results show that ED binds the novel methyltrienolone (R1881) binding protein of JEG-3 cells with higher affinity than any other natural steroids tested. Furthermore, ED is able to inhibit transcriptional activity of the estrogen-receptor-related receptors alpha and gamma, suggesting that ED may be the natural ligand of these orphan receptors. ED is also able to activate the xenobiotic receptor SXR. Chemical analysis of the fine structural features of purified ED is in progress.

Preterm birth is the major clinical issue in maternal-child health in the developed and developing world. Even though multiple factors have been identified as causes of spontaneous preterm labour, the specific events leading to preterm birth are still poorly understood. Our group has previously identified a novel endogenous steroid, estradienolone (ED), and reported that the plasma and placental levels of ED remain high during pregnancy and decrease in association with term and preterm labour. Since ED appears to have progestin-like properties and is a natural ligand of estrogen receptor-related orphan receptors, ED may play a role in the maintenance of pregnancy or its decrease in the initiation of parturition. To fully analyze the unique biological properties of ED, availability of large quantities of ED by chemical synthesis is required. Although mass spectrometric analysis revealed an estradienolone structure, details such as position of double bonds and absence of other subgroups are necessary before chemical synthesis can be attempted. The objective of the current project was to prepare sufficient quantities of pure ED for detailed structural analysis. Early studies focused on purifying unconjugated ED from hydrolysed pregnancy urine since it is an abundant source of sulfate-conjugated ED. However, the yield of unconjugated ED was low probably due to its relatively unstable nature. Several methodologies were therefore developed for the isolation of ED sulfate as it is a more stable form of ED. Availability of sufficient quantities of ED or ED sulfate are critical for defining the detailed structure (using methods such as nuclear magnetic resonance), of this novel steroid. / Les naissances prématurées sont un problème clinique majeur en maternité/pédiatrie dans les pays développés et en voie de développement. Bien que de nombreux facteurs de risques d'accouchement prématuré spontané aient été identifiés, les évènements spécifiques conduisant à une naissance avant terme sont encore mal compris. Notre groupe a identifié précédemment un nouveau stéroïde endogène, l'estradienolone (ED), et a montré que les niveaux placentaires et du plasma d'ED restent élevés pendant la grossesse et chutent en association avec le travail prématuré ou à terme. Puisqu'ED possède des caractéristiques semblables à la progestérone et est un ligand naturel des récepteurs orphelins associés à l'œstrogène (ERR), il est possible qu'ED joue un rôle dans le maintien de la grossesse. Sa diminution entrainerait alors le déclenchement de la parturition. Afin de finir de caractériser les propriétés biologiques uniques d'ED, il nous faut le synthétiser chimiquement en grandes quantités. Cependant, bien que l'analyse par spectrométrie de masse ait indiqué qu'ED a une structure d'estradienolone, la position des liaisons doubles et la présence ou absence d'autres sous-groupes restent à déterminer avant de pouvoir effectuer une telle synthèse chimique d'ED. L'objectif de ce projet était donc de préparer des quantités suffisantes d'ED pur en vue de réaliser une analyse structurale détaillée. Nous avons d'abord essayé de purifier ED non conjugué après hydrolyse d'urine de femme enceinte, puisque c'est une source importante d'ED conjugué à un groupement sulfate (sulfate d'ED). Le faible rendement d'ED non conjugué (probablement dû à sa nature relativement instable) m'ont conduit à développer d'autres techniques pour l'isoler le sulfate d'ED car cette forme est plus stable. La disponibilité de quantités suffisantes de sulfates d'ED ou d'ED non conjugué est essentielle pour l'obtention de la structure détaillée de ce nouveau stéroïde (en employant des méthodes telles que la résonance magnétique nucléaire).

One of the crucial events during mammalian embryogenesis is the process of implantation. Implantation enables the embryo to invade the uterine endometrium and to gain access to the maternal circulation. The attachment reaction requires a highly coordinated dialogue between the implanting blastocyst and the receptive uterus, known as the embryo-uterine cross-talk. Since the blastocyst expresses multiple Wnt genes, in this study, we have characterized the role and regulation of the Wnt/-catenin pathway in embryo-uterine communication. Using a transgenic mouse that reports Wnt signalling through the canonical pathway, we have demonstrated that the Wnt/-catenin pathway was transiently activated in the regions of the uterine luminal epithelium apposed to the blastocyst at the time of implantation. Activation of this pathway within the endometrium depended on the presence of the blastocyst and required the oestrogen surge. We further demonstrated that activation of the Wnt/-catenin pathway was essential for proper implantation to occur. One possible mechanism that regulates the responsiveness of the luminal epithelium to Wnt is the regulation of components of the Wnt pathway. We show that there is dynamic pattern of expression of the components of the Wnt pathway at the time of implantation. Furthermore, we demonstrate that LIF signalling is required for the expression of a subset of these Wnt components in luminal epithelial cells at the time of implantation. Our results demonstrate that the LIF and Wnt signalling pathway form a network involved in coordinating the process of implantation As Wnt/ß-catenin signalling is essential for embryo attachment, we proposed / Le processus de l'implantation embryonnaire joue un rôle crucial lors du développement des mammifères. L'implantation de l'embryon est un processus extrêmement complexe au cours duquel l'embryon va d'abord s'apposer, puis adhérer à l'endomètre pour ensuite y pénétrer. Ultérieurement, il a été démontré que le blastocyste exprime plusieurs gènes de la famille Wnt. C'est pour cette raison que dans cette thèse, j'ai décidé caractériser le rôle et la régulation de la voie de signalisation Wnt/-catenine lors du dialogue materno-fœtal. Nous avons utilisé une souris transgénique qui permet de contrôler la voie de signalisation Wnt/-catenine. Ainsi, nous avons démontré que la voie de signalisation Wnt/-catenine était activée de façon transitoire dans les cellules épithéliales du lumen de l'utérus, dans la région adjacente au blastocyte au moment de l'implantation. L'activation de cette voie de signalisation dépend de la présence du blastocyste et de la sécrétion d'oestradiol. Nous avons également démontré que l'activation de la voie de signalisation Wnt/-catenine était essentielle au processus d'implantation embryonnaire. Par la suite, nous avons examiné la possible interaction entre la voie de signalisation Wnt et LIF. En effet, dans les souris mutantes pour le gène LIF, la voie de signalisation Wnt/-catenine n'est pas activée. Grâce à la technique de rt-PCR, nous avons caractérisé le profil d'expression des récepteurs Frizzled, des co-récepteurs LRP, des antagonistes sFRP et DKK et des gènes Wnt dans les souris mutantes pour le gène LIF et dans les souris de type sauvage. Nous avons démontré que les composa

My three papers evaluate the effectiveness and cost-effectiveness of clinical and policy strategies to improve women’s health, focusing on human papillomavirus (HPV) vaccination in the U.S. and maternal health care in a developing country context. Paper 1 presents a claims-based econometric analysis of the U.S.’s Patient Protection and Affordable Care Act provision requiring the elimination of cost-sharing for recommended preventive care. I evaluate the effect of this value-based insurance design intervention on HPV immunization rates among girls and young women enrolled in private insurance plans. My regression approach uses variation in the intensity and timing of the intervention across plans to distinguish policy effects from background trends. I find that the policy was associated with modest increases in age-specific vaccination rates. Increases in vaccination per dollar reduction in cost-sharing were notably larger among beneficiaries in socioeconomically disadvantaged areas. Nevertheless, vaccination rates under free preventive care were well below federal targets, highlighting the need for additional interventions to increase HPV vaccine coverage. In Paper 2, I undertake a comparative effectiveness analysis of HPV vaccination by dose level within a U.S. cohort of adolescent girls and young women. Rates of screening-detected cervical abnormalities in claims are compared among recipients of zero, one, two, or three doses, using a marginal structural model approach to adjust for a broader set of potential confounders than would be possible with conventional regression methods. Findings from these analyses complement prior evidence from immunogenicity trials, and although protective effects appear greatest with three doses, support the value of HPV vaccination even when incomplete. Vaccine effect estimates are largest with respect to high-grade lesions that are precursors to cervical cancer. Using primary data from a randomized experiment, Paper 3 examines the cost-effectiveness of pay-for-performance interventions among obstetric care providers in rural Karnataka, India. I construct a decision analytic model to quantify incremental costs and life years under alternative policy scenarios, combining obstetric complication outcomes and program expenditures from the trial with published evidence on complication-related mortality and medical costs. Results suggest that an incentive program based on input quality is not cost-effective in its current form, but could become economically attractive if program activities can be adjusted to reduce costs while maintaining similar health effects. Performance data collection costs were substantial in this resource-limited setting and represent a key barrier to cost-effectiveness. / Health Policy

Postmenopausal women rely on hormone replacement therapy to manage menopausal symptoms. Few studies have assessed the consequences of estrogen progestin replacement therapy (EPRT), a formulation prescribed to postmenopausal women with an intact uterus. The aim of this thesis was to conduct a systematic review and meta-analysis assessing the association between breast cancer risk and EPRT use among postmenopausal women. Electronic databases, handsearching and advice from experts were used to locate studies. A fixed effects model was used to calculate the combined estimate and its standard error. Statistical tests for association and homogeneity were performed. The association between breast cancer risk and EPRT exposure was significant for both case control (OR = 1.38; 95% CI 1.23--1.56; chi2 = 48.30, p < 0.0001) and cohort studies (RR = 1.42; 95% CI 1.29--1.57; chi 2 = 27.95, p < 0.0001). Results indicate that postmenopausal women on EPRT have a higher breast cancer risk, particularly with long term use and testosterone derived formulations.

This Ph.D. project sought to determine the expression, regulation, and function of the KIT-SCF receptor-ligand system in human epithelia] ovarian cancer. The expression of c- KIT and SCF in normal ovaries, in cultured ovarian surface epithelium (OSE), and in epithelia] ovarian tumors was analyzed. Normal OSE expressed SCF, but not c- KIT ; however, epithelia] invaginations and inclusion cysts often expressed KIT protein. Of 15 benign ovarian tumors and tumors of low malignant potential, 87% expressed c- KIT , and 92% of these co-expressed SCF, suggesting the possibility of autocrine growth regulation. Of 35 malignant ovarian cancers, 71% expressed c- KIT (92% co-expressed SCF), with a trend for decreased c- KIT expression in advanced stage disease. Of 34 patients with malignant tumors for whom follow-up information was available (median follow-up time of 24 months), 9 had tumors that did not express c- KIT , 8 (89%) of whom have died and the remaining 1 has recurrent disease. Of the 25 patients with tumors expressing c- KIT , 56% are still alive, eight of whom have no evidence of disease. Importantly, statistical analysis indicated that patients whose tumors did not express c- KIT had a significantly shorter (p < 0.05) disease-free survival time than patients who had KIT-expressing tumors. Studies were carried out to identify intraovarian growth regulatory factors which may regulate c- KIT and SCF expression in ovarian cancer cells, and to determine whether activated KIT can affect the proliferation and survival of these cells. HEY cells, which co-expressed KIT and SCF, were treated with transforming growth factor (TGF)-α, TGF-β, and dibutyryl cyclic AMP (dbcAMP) and their cellular proliferation and expression of c- KIT and SCF were examined. A series of transfection studies were carried out to determine if enforced c- kit expression inhuman ovarian carcinoma cells could regulate cellular proliferation. Transient transfection of c- kit into HEY cells resulted in decreased proliferation. Similarly, stable transfection of c- kit into A2780-cp cells, which do not express endogenous c- KIT , also resulted in a decreased proliferative rate. In contrast to the ovarian cancer cells, increased proliferation was documented for NIH 3T3 fibroblast cells transiently transfected with c- kit . Together, these results suggest that the positive prognostic value of c- KIT expression in ovarian tumors is related to its negative growth regulatory function in ovarian cancer cells. (Abstract shortened by UMI.)

Abstract Not Available.

Background. Decision support interventions (DSIs) are interventions used by patients and their practitioners to help make difficult shared healthcare decisions. The efficacy of these interventions is well established. However, there are no formal comparisons of the efficacy of different delivery methods. Interactive computerized delivery methods have the advantage of allowing patients to control the flow of information and to receive feedback on their comprehension. Objective. To compare the efficacy of an interactive computerized DSI for women considering long term hormone replacement therapy (HRT), to that of a validated audio-booklet-based version of the same intervention. Study design. Fifty-one peri- and post-menopausal women aged 40--70 who were literate in English, and who showed no evidence of cognitive impairment, were randomized to use either the computerized or the standard audio-booklet version of the DSI. The patients were interviewed with a pre- and post-intervention questionnaire. Interventions. (1) Standard audio-booklet-based decision aid: A 40-minute audio tape guided participants through an illustrated booklet describing the risks and benefits of post-menopausal HRT. (2) Interactive computer based decision aid: The computerized version of the DSI presents identical information as synchronized text/audio/animation. (Abstract shortened by UMI.)

Le but de l'étude consiste à évaluer auprès de femmes francophones l'efficacité d'un support d'aide à la décision sur la qualité de la prise de décision en regard de l'hormonothérapie substitutive. Une expérimentation avec un devis avant-après avec groupe unique a été menée auprès de 40 femmes âgées de 47 à 64 ans. Les variables à l'étude ont été mesurées à l'aide des questionnaires et des échelles de mesures portant sur: (1) les connaissances; (2) les attentes; (3) les valeurs; et (4) le niveau de conflit décisionnel en regard des bénéfices et des risques de l'hormonothérapie substitutive. Les résultats de cette étude révèlent une amélioration significative ( p < 0,05) des connaissances et une amélioration des attentes réalistes de la femme par rapport aux risques et aux bénéfices de l'hormonothérapie, après l'utilisation du support d'aide à la décision. Quant aux valeurs, les résultats révèlent une meilleure cohérence des valeurs de la femme par rapport à l'hormonothérapie après l'intervention. Enfin, les résultats démontrent, en général, une diminution significative du niveau de conflit décisionnel. Les femmes se sentent plus informées, supportées et ont la perception qu'elles ont pris une décision efficace. Les résultats de cette étude suggèrent que l'utilisation d'un support d'aide à la décision chez les femmes ménopausées contribue à l'amélioration de la qualité de la prise de décision par rapport à l'hormonothérapie substitutive. Cette étude doit être considérée comme un projet pilote, lequel devra être suivi d'une étude auprès d'un plus grand échantillon afin d'examiner la généralisation possible des résultats à l'ensemble de la population féminine francophone.