This research was conducted to test the hypothesis that parenteralarginine supplementation is effective in enhancing birth weights of intrauterinegrowth restricted (IUGR) fetuses. Underfed and prolific ewes were used asexperimental models. The first study characterized the pharmacokinetics ofarginine and citrulline and assessed the potential of citrulline to serve as aprecursor for enhancing arginine availability in fetal and maternal plasma. Sixlate pregnant ewes and their fetuses were instrumented to access arterial andvenous circulations. Intravenous boluses of 155 mol of L-arginine-HCl or Lcitrullineper kg body weight were administered to each ewe. Administration ofcitrulline was more effective than arginine in achieving a sustained increase inconcentrations of arginine in maternal and fetal blood. Accordingly, theclearance rate of citrulline was lower and its biological half-life in maternal bloodgreater, when compared with arginine. The second experiment determined ifadministration of arginine to underfed ewes is effective in ameliorating orpreventing IUGR. Ewes were fed either 100% or 50% of the National ResearchCouncil recommended nutrient requirements for pregnant sheep. Between Day60 of pregnancy and parturition control-fed ewes received saline solution and underfed ewes received either saline solution or L-arginine-HCl solution (155mol of arginine/kg body weight) intravenously three times daily (n=5 / treatmentgroup). Birth weights of lambs were lower in saline-infused underfed ewes.There was no difference in birth weights of lambs from control-fed and argininetreatedunderfed ewes. The third experiment determined whether administrationof arginine could improve survival rates of lambs and enhance fetal growth inewes carrying multiple fetuses. Between Days 100 and 121 of pregnancy, ewesreceived an intravenous infusion of either saline solution (n= 14) or L-arginine-HCl solution (345 mol of arginine/kg body weight, n=20) three times daily.Parenteral administration of arginine increased the percentage of lambs bornalive and enhanced the birth weights of quadruplets. Collectively, these resultsindicate that 1) parenteral administration of arginine improves pregnancyoutcomes in underfed and prolific ewes; and 2) the use of arginine or citrullinemay have important implications for the design of an effective treatment forpreventing or ameliorating IUGR in mammals.

This research was conducted to test the hypothesis that parenteralarginine supplementation is effective in enhancing birth weights of intrauterinegrowth restricted (IUGR) fetuses. Underfed and prolific ewes were used asexperimental models. The first study characterized the pharmacokinetics ofarginine and citrulline and assessed the potential of citrulline to serve as aprecursor for enhancing arginine availability in fetal and maternal plasma. Sixlate pregnant ewes and their fetuses were instrumented to access arterial andvenous circulations. Intravenous boluses of 155 mol of L-arginine-HCl or Lcitrullineper kg body weight were administered to each ewe. Administration ofcitrulline was more effective than arginine in achieving a sustained increase inconcentrations of arginine in maternal and fetal blood. Accordingly, theclearance rate of citrulline was lower and its biological half-life in maternal bloodgreater, when compared with arginine. The second experiment determined ifadministration of arginine to underfed ewes is effective in ameliorating orpreventing IUGR. Ewes were fed either 100% or 50% of the National ResearchCouncil recommended nutrient requirements for pregnant sheep. Between Day60 of pregnancy and parturition control-fed ewes received saline solution and underfed ewes received either saline solution or L-arginine-HCl solution (155mol of arginine/kg body weight) intravenously three times daily (n=5 / treatmentgroup). Birth weights of lambs were lower in saline-infused underfed ewes.There was no difference in birth weights of lambs from control-fed and argininetreatedunderfed ewes. The third experiment determined whether administrationof arginine could improve survival rates of lambs and enhance fetal growth inewes carrying multiple fetuses. Between Days 100 and 121 of pregnancy, ewesreceived an intravenous infusion of either saline solution (n= 14) or L-arginine-HCl solution (345 mol of arginine/kg body weight, n=20) three times daily.Parenteral administration of arginine increased the percentage of lambs bornalive and enhanced the birth weights of quadruplets. Collectively, these resultsindicate that 1) parenteral administration of arginine improves pregnancyoutcomes in underfed and prolific ewes; and 2) the use of arginine or citrullinemay have important implications for the design of an effective treatment forpreventing or ameliorating IUGR in mammals.

Diss. (sammanfattning) Uppsala : Uppsala universitet, 2006. / Härtill 5 uppsatser.

Fetal growth in utero depends on nutrient and oxygen reaching the fetus through the uterine and placental microcirculations, both undergoing massive expansion during pregnancy. Aberrations of the placental vasculature are associated with Intrauterine Growth Restriction (IUGR), a common pathological outcome of pregnancy; however, the cellular components responsible for vessel formation in the placenta and the uterus remain unknown. Endothelial Progenitor Cells (EPC) are a group of morphologically and functionally varied bone marrow derived vasculogenic cell types, divided into two major subsets: (i) Circulating Angiogenic Cells (CACs), which promote vessel formation by interfering with the extracellular matrix and (ii) Endothelial Colony Forming Cells (ECFCs), which provide the source for new endothelium. This role has been demonstrated in pathophysiological studies, but not in normal physiological events in vivo. Fetal ECFCs are more proficient than their adult counterparts, but it is unclear in what specific fetal or maternal physiological situations fetal ECFCs are involved. Based upon these considerations, it was hypothesised that: (i) fetal-derived ECFCs play a role in placental vasculogenesis, (ii) these cells transmigrate the placenta and home to loci of vessel formation in the pregnant uterus, and that (iii) intrinsic alterations in their capabilities are associated with fetal growth restriction during intrauterine life. To support these hypotheses the following experiments were performed;(i) EPCs in blood from pairs of human umbilical arteries and veins were counted by flow cytometry. Numbers of EPCs in these samples showed an arterio-venous gradient suggesting their placental sequestration. Furthermore, ECFCs were isolated from human umbilical blood using established culture techniques. Labelled human fetal ECFCs were transplanted into the circulation of murine fetuses using an ultrasound-guided intra-cardiac injection. Using a fluorescent imager and microscopy these cells were shown to home to the murine placenta and participate in vasculogenesis.(ii) Male mice ubiquitously expressing eGFP were crossbred with native females, and fetal (eGFP-positive) endothelial-like cells integrated into the uterine microvasculature. Human fetal ECFCs injected into murine fetuses were shown to migrate to the maternal uterus and became functionally involved with the microvasculature. In humans, microvessels were isolated from uterine biopsies of mothers with male offspring. Copies of the male specific SRY gene (quantified by RT-QPCR) indicated that cells of fetal origin constituted 12% of the endothelium in these vessels. In cross-sections, hybridisation of the Y-chromosome demonstrated the presence of fetal cells in the maternal endothelium of the human uterus. (iii) Using flow cytometry, fewer EPCs were defined within the peripheral circulation of growth-restricted babies. Functional assays showed that ECFCs derived from these growth-restricted cases had intrinsically impaired proliferation, migration, matrix-metalloproteinase (MMP-2) production, and generated fewer blood vessels in a murine vasculogenic bioassay. These results demonstrated the vasculogenic capacity of human fetal ECFCs in vivo and established them as key players in human placental vasculogenesis and uterine vessel expansion. Notably, these results also showed a link between impaired function of fetal ECFCs and IUGR, which is associated with increased cardiovascular risk of both the fetus as an adult, and mother in later life. From these findings it could be speculated, that intrinsic changes in ECFC-biology may be the causative link between IUGR and fetal and maternal cardiovascular susceptibility. Insight into these processes may contribute to early diagnosis, prevention and treatment of IUGR and associated conditions.

Background: Despite a wide range of contraceptive options available in the United Kingdom, the unplanned pregnancy rate remains high. Contraceptive services are currently delivered by general practitioners, sexual health clinics and pharmacies, but there may be scope to expand the places that these are offered, and increase the options available within each service. Doing so could increase the uptake of contraceptive methods, particularly the most effective methods, and therefore reduce the unplanned pregnancy rate. Aim and objectives: Research in this thesis aimed to investigate novel delivery models of contraception. The research had two main areas of focus. Firstly the capacity of the pharmacy to deliver regular contraception was examined, in the context of existing literature, and then through a pilot study. After that the expansion of contraception care to maternity services was investigated, first in the literature and then using an observational study. Methods: In undertaking this thesis I used a variety of methods. Two patient surveys were employed to investigate patients’ perspectives on proposed novel methods of contraceptive delivery. A pilot study investigated the feasibility and acceptability of delivery of the contraceptive injection at the pharmacy. Quantitative results about the numbers of injections given were collected, as were patient questionnaires. Qualitative one-to-one interviews were conducted with participating pharmacists, these were recorded, transcribed and analysed. An observational study was also undertaken to assess routine delivery of insertion of intra-uterine contraception at the time of caesarean section. Patients were seen at six weeks following insertion, and contacted by telephone at three, six and 12 months about satisfaction and continuation of the method. Results: 220 women completed a questionnaire about attending the community pharmacy to receive a contraception injection. 33% of current non-users indicated that they would consider using this method if it was available at the pharmacy. 50 established users of the contraceptive injection participated in a pilot project receiving up to three injections from the community pharmacy. Only 48 injections of a possible 150 were delivered at the community pharmacy. Only 7 participants received all three injections at the pharmacy, and participants reported mixed experiences accessing the pharmacy. The practical obstacles around pharmacy engagement and the challenges of retaining participants were significant, and more research is necessary before proceeding with a randomised controlled trial. 250 women on a postnatal ward completed questionnaires about their pregnancy intentions. 96.7% were not planning a baby in the next year, but only 23.6% were planning on using the most effective methods of contraception. One in three respondents described themselves as likely to use either an implant or intra-uterine contraception if it could be inserted before they left the hospital. In an observational study, 120/877 women opted to have intra-uterine contraception inserted at the time of caesarean section. Continuation rates at 12 months were 84.8% of those contacted, and 92.6% were either ‘very’ or ‘fairly’ happy with their contraception. Conclusion: Although patients are receptive to contraception being delivered using novel service models, alternatives to current practice need careful investigation. Contraceptive injections at the community pharmacy are not necessarily more convenient for patients, and therefore may not increase uptake of this method. However, offering intrauterine contraception to patients at the time of caesarean section is highly acceptable to patients, and results in a substantial majority continuing this highly effective method. Robust and careful research using a range of methods can help to identify which innovative approaches to contraceptive delivery offer the most promise.

We established that acute adrenergic receptor stimulation in β-cells suppresses oxidative metabolism. This effect provides the basis for understanding how CAs reduce cell proliferation. Furthermore, the effects of acute CA on Min6 cells were distinguished from chronic CA culture using proteomics. Together, the RNAseq, qPCR and proteomic studies support a role for adrenergic receptor signaling in the regulation of proliferaton in β-cells. This work describes the genetic and proteomic profile underlying chronic adrenergic signaling and identifies CA independent suppression of β-cell growth and metabolism. Through the use of multiple models and comparative bioinformatics, we refined the list of molecular dysfunctions associated with the IUGR pathology to a set of specific and testable adrenergic targets.

Current research spans a wide range of objectives whose diversity includes the understanding of global epidemiology and the detailing of molecular interactions leading to specific pathologies. This work aligns more closely with the goal of mechanistic clarity by elucidating several aspects of signaling pathways involved in inflammatory and obstetric pathologies. Prior research has confirmed the role of Receptors for Advanced Glycation End-Products (RAGE) activation in signaling leading to chronic inflammation such as that observed in chronic obstructive pulmonary disease (COPD). RAGE activation has also been identified in other disease states including diabetes, Alzheimer’s disease, osteoarthritis, and cancers. We examined the role of RAGE in the obstetric complication intrauterine growth restriction (IUGR) wherein fetal development is delayed and infants are born at low birthweight. Exposure to tobacco smoke is known to activate RAGE, and smoke exposure also increases risk for IUGR. We confirm a role for RAGE signaling in development of IUGR. RAGE inhibition by semi-synthetic glycosaminoglycan ethers (SAGEs) significantly improved fetal and placental weights and reduced inflammatory signaling molecules. Interactions between RAGE and other signaling pathways have been noted in several research endeavors, and we sought to further understand signaling interactions specifically in obstetric pathologies by examining relationships between RAGE and Gas6/AXL signaling. We confirm that RAGE and Gas6/AXL signaling are not independent. Using tobacco smoke as a means of inducing RAGE, we determined that total AXL is inhibited when RAGE is active, but that phosphorylated AXL is increased. Inhibition of RAGE also increased Gas6 expression. These interactions require further clarification, but provide a foundation to expand upon. We further studied interactions within the Gas6/AXL pathway independent of RAGE. High levels of Gas6 have been noted in the serum of some women with preeclampsia, and early diagnosis and treatment of preeclampsia are currently limited. We demonstrate that, in a rat model, administration of Gas6 during pregnancy is sufficient to induce symptoms of preeclampsia including high blood pressure, increased proteinuria, and decreased trophoblast invasion. This provides a novel model which will further both diagnosis and treatment of preeclampsia. We also demonstrated that trophoblast invasion is influenced in a cell-type dependent manner by Gas6 and mTOR signaling, with decreased trophoblast invasion when Gas6 is high in trophoblast cells, but increased invasion with high Gas6 in a pulmonary adenocarcinoma cell type and in oral squamous cell carcinoma cells. Our work has clarified details of both RAGE and Gas6/AXL signaling that are crucial to further study of the pathways in which they are active, and the pathologies resulting from signaling misregulation.

京都大学 / 新制・論文博士 / 博士(医学) / 乙第13514号 / 論医博第2264号 / 新制||医||1061(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 萩原 正敏, 教授 湊谷 謙司, 教授 中島 貴子 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM

No description available.

Source: Dissertation Abstracts International, Volume: 69-10, Section: B, page: 6009. Adviser: Dorothy K. Waller. Includes bibliographical references.