No description available.

The mechanisms which control the accumulation and circulation of the amniotic fluid are poorly understood. Earlier studies had made the tentative suggestion that vasopressin, which is important in the control of water balance in adults, might play a role in the regulation of amniotic fluid turnover. In the work reported here, attempts were made to detect and measure the vasopressin levels in the amniotic fluid of guinea pigs, sheep and humans. Unconcentrated amniotic fluid samples from the guinea pig, sheep and human were assayed using the water-loaded, alcohol-anesthetized rat antidiuretic preparation. If vasopressin is present in the fluid of these animals, it would be at a concentration below the detectable limits of the assay, which were found to be 10 to 15 microunits/ml. Only 4 out of 36 experiments on guinea pig amniotic fluid gave even a suggestion of a response, with 3 of these being too small to be quantified accurately. No sheep or human samples produced an antidiuresis. An attempt was made to dehydrate the maternal guinea pigs, as it. was thought that this would create an osmotic stress in the fetus which might result in increased output of vasopressin. In 29 experiments with fluid of fetuses whose mothers had been without water for 24 or 48 hours prior to collection, 27 gave no response. The responses to the two injections that did indicate activity were too low for accurate quantification. However, these experiments were not considered conclusive, and more extended investigation is needed. Seven human amniotic fluid samples were concentrated on CM-25 Sephadex columns, along with three standard vasopressin loads. The standards showed recoveries of 80% to 90% under optimal conditions. An antidiuretic substance was found in fractions from all of these samples, and it eluted at a similar pH and molarity to the standard vasopressin. This material measured approximately 200 micro-units/ml, and was relatively consistent in all of the samples tested. The amniotic fluid antidiuretic substance (AFAS) appeared to respond with an antidiuresis similar to that of vasopressin on the assay preparation. However, further work suggested that the AFAS could not be identified as vasopressin. Although the pattern of antidiuretic responses were similar, there were marked changes in the sensitivity of the bioassay preparation to the unknown material during periods of little change in the responses to vasopressin itself. A similar contrast was found between different experiments. Sodium thioglycollate incubation also failed to deactivate the active AFAS fractions, whilst control volumes of vasopressin lost apparently all activity following this procedure. The stability characteristics were also dissimilar to those of vasopressin, as the fractions remained active for up to five weeks when stored at neutral pH at 4° C. Optimum pH conditions for the storage of vasopressin are between 3.0 and 5.0. An attempt was made to identify the AFAS as angiotensin II. However, the response pattern on the records of the antidiuretic assay were dissimilar. Further comparisons with combinations of vasopressin and angiotensin II in varying concentrations also failed to mimic the responses to the AFAS. It was concluded that the antidiuretic activity found in the human amniotic fluid was not attributable to vasopressin, angiotensin II, or to a combination of these two hormones, at the levels tested. The nature of the AFAS is at present unknown. Further studies are needed to identify the unknown antidiuretic agent extracted from human amniotic fluid, and the possible mechanisms of its release, and its potential physiological functions, are still unknown. / Science, Faculty of / Zoology, Department of / Graduate

Thesis (Ph. D.)--University of Washington, 1997. / Vita. Includes bibliographical references (leaves [101]-111).

Made available in DSpace on 2014-06-11T19:29:17Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-02-20Bitstream added on 2014-06-13T19:38:35Z : No. of bitstreams: 1 moya_cf_me_botfmvz.pdf: 156959 bytes, checksum: 8445a2c6b5b162a42c66e3322c1bbd52 (MD5) / A proposta do presente estudo foi descrever as diferenças no padrão morfológico das células do fluido amniótico, no momento do parto. Comparando os resultados obtidos de bezerros nelores oriundos de produção in vitro, transferência de embriões e inseminação artificial. Utilizaram-se 60 animais, divididos em Grupo 01: vinte vacas inovuladas com embriões Nelore produzidos in vitro (PIV) a partir de colheita de oócitos por aspiração folicular de doadoras, Grupo 02: vinte vacas gestando bezerros nelores originados de inovulações de embriões oriundos de doadoras superovuladas pelo método convencional, e Grupo 03: vinte vacas nelores PO gestando bezerros oriundos de inseminação artificial (controle). Próximo ao parto as vacas foram transferidas para piquete maternidade com acompanhamento dos partos. Durante a fase de expulsão e após a ruptura do alantocórion realizou-se a punção do âmnion para colheita de 20mL de liquido, que foi depositado em tubo plástico e congelado em freezer. Para a classificação celular as amostras, pós-descongelação, foram centrifugadas na Citocentrifuga (Revan Centrifuga Ciclo Cito) a 4000rpm durante seis minutos e empregou-se a técnica de coloração Hematoxilina-Shorr. Ao final deste procedimento, as lâminas citológicas foram montadas com lamínulas empregando Bálsamo do Canadá e posteriormente (após o período de secagem) observadas em microscópio óptico com aumentos de 200x e 400x para visualização das características morfológicas e tintoriais das células epiteliais do feto. Para avaliação da maturidade epidérmica utilizou-se a técnica de coloração de Sulfato Azul do Nilo bem como a porcentagem de células queratinizadas (coloração Hematoxilina-Shorr). As células basais e parabasais não foram encontradas nas lâminas citológicas das amostras de líquido amniótico analisadas... / The aim of the present study was to describe the differences in the cytological pattern of the amniotic fluid, at the moment of delivery, comparing the data from Nelore calves obtained by in vitro production, embryo transfer and artificial insemination. Sixty (n=60) Nelore cows were divided in group 01: Twenty cows (n=20) pregnant with Nelore calves obtained by in vitro production (IVP) after follicular aspiration; group 02: Twenty cows (n=20) pregnant with Nelore calves obtained by superovulation of embryo donors (ET); group 03: Twenty Nelore cows (n=20) pregnant of calves obtained by artificial insemination (AI; control). Near to the labor, the cows were transferred to a maternal paddock, permitting delivery observation. During the expulsion phase, after the rupture of the alantochorion the amnion was punctured and 20ml of fluid were collected in a plastic device and frozen. The samples, after being thawed, were centrifuged at 4000 rpm, during 06 minutes the Hematoxilin-Shorr stain was applied, after this, the glass slides were covered with Canadian balsame and analyzed in optical microscopy. To the evaluation of the epidermal maturity were used the Blue Nile Sulfate stain, as well the percent of keratinizaded cells observed in the Hematoxilin-Shorr stain. The basal and parabasal cells were not found on the slides of the amniotic fluid samples analyzed. The small intermediate cells (CIP) had its shape as an oval or polygonal form with large cytoplasm and central nucleus. The large intermediate cell (CIG) showed a central nucleus and a bigger nucleus-cytoplasm relation compared to the superficial cells. These were the largest cells found. They showed keratinization with angular edges, having both a picnotic nucleus (CSN) and no nucleus at all. (CSA). The technique of Blue Nile Sulfate stain did not showed satisfactory for the evaluation of the fetal maturity, in spite of some records... (Complete abstract click electronic access below)

Wong Chi Ho. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 74-94). / Abstracts in English and Chinese. / Tittle / Table of contents / Acknowledgment / Abstract / Chapter Chapter 1. --- Introduction --- p.1 / Chapter Chapter 2. --- Literature Reviews --- p.2 / Chapter 2.1 --- Sonographic history --- p.2 / Chapter 2.1.1 --- Definition of ultrasound --- p.2 / Chapter 2.1.2 --- History of general ultrasonography --- p.2 / Chapter 2.1.3 --- Early history of fetal diagnostic ultrasonography --- p.4 / Chapter 2.2 --- Placental sonography --- p.10 / Chapter 2.2.1 --- Development of the placenta --- p.10 / Chapter 2.2.2 --- Sonographic placental development --- p.12 / Chapter 2.2.3 --- Placental grading --- p.14 / Chapter 2.2.3.1 --- Early studies of the placenta --- p.14 / Chapter 2.2.3.2 --- Placental grading --- p.16 / Chapter 2.2.3.3 --- Placental grading and gestational age --- p.18 / Chapter 2.2.3.4 --- Placental grade and neonatal outcome --- p.20 / Chapter 2.2.4 --- Placental thickness --- p.22 / Chapter 2.3 --- Amniotic fluid --- p.24 / Chapter 2.3.1 --- Amniotic fluid dynamics --- p.24 / Chapter 2.3.2 --- Methods of sonographic assessment of amniotic fluid --- p.28 / Chapter 2.3.3 --- Correlation of AFI with clinical oligohydramnios --- p.30 / Chapter 2.3.4 --- Clinical outcome associated with oligohydramnios --- p.32 / Chapter Chapter 3. --- Methodology --- p.34 / Chapter 3.1 --- Introduction --- p.34 / Chapter 3.2 --- Criteria for patients selection --- p.35 / Chapter 3.3 --- Calculation of the gestational age --- p.35 / Chapter 3.3.1 --- Measurement of bipatietal diameter (BPD) --- p.36 / Chapter 3.4 --- Ultrasonic measurements of the placenta and amniotic fluid --- p.37 / Chapter 3.4.1 --- Placental grading --- p.37 / Chapter 3.4.2 --- Placental thickness --- p.38 / Chapter 3.4.3 --- Amniotic fluid index --- p.39 / Chapter 3.5 --- Statistical analysis --- p.39 / Chapter 3.5.1 --- Amniotic fluid index --- p.39 / Chapter 3.5.2 --- Placental thickness --- p.40 / Chapter 3.5.3 --- Clinical outcome --- p.41 / Chapter Chapter 4. --- Results --- p.42 / Chapter 4.1 --- Overall obstetric demographic characteristics of study population --- p.44 / Chapter 4.2 --- "Gestation-related changes in placental grade, placental thickness and amniotic fluid index" --- p.48 / Chapter 4.2.1 --- "Amniotic fluid index, gestational age and maternal characteristics" --- p.48 / Chapter 4.2.2 --- Placental thickness --- p.53 / Chapter 4.2.3 --- Placental grades and gestational age --- p.57 / Chapter 4.3 --- The clinical outcomes and ultrasound parameters --- p.61 / Chapter Chapter 5. --- Discussion --- p.63 / Chapter 5.1 --- Gestation related change of AFI and maternal characteristics --- p.63 / Chapter 5.2 --- Placental grade and gestational age --- p.67 / Chapter 5.3 --- Placental thickness --- p.72 / Chapter Chapter 6. --- Reference --- p.74 / Graphics --- p.95 / Figure 1 Grannum's placental grading system / Figure 2 Amniotic fluid index against gestational age / Figure 3 Placental thickness versus gestational age / Figure 4 Graph of placental grades versus progressing gestational age / Figure 5 Median amniotic fluid index in four populations

Liu Bao Yi. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 83-104). / Abstracts in English and Chinese. / ABSTRACT --- p.i / ACKNOWLEDGEMENT --- p.v / TABLE OF CONTENTS --- p.vi / LIST OF ABBREVIATIONS --- p.xii / LIST OF FIGURES --- p.xivv / LIST OF TABLES --- p.xv / PUBLICATION RELATED TO THIS THESIS --- p.xvii / Chapter PART 1 --- INTRODUCTION AND LITERATURE RESEARCH / Chapter CHAPTER 1 --- INTRODUCTION --- p.1 / Chapter CHAPTER 2 --- MECONIUM STAINED LIQUOR --- p.3 / Chapter 2.1 --- AMNIOTIC FLUID --- p.3 / Chapter 2.1.1 --- Function of Amniotic Fluid --- p.3 / Chapter 2.1.2 --- Composition Of Amniotic Fluid --- p.3 / Chapter 2.1.3 --- Regulation Of Amniotic Fluid --- p.4 / Chapter 2.1.4 --- Abnormality Of Amniotic Fluid Volume --- p.4 / Chapter 2.2 --- MECONIUM STAINED LIQUOR --- p.6 / Chapter 2.2.1 --- Formation And Composition Of Meconium --- p.6 / Chapter 2.2.2 --- Peristalsis Of Fetal Gastrointestinal Tract --- p.7 / Chapter 2.2.3 --- Meconium Stained Liquor(MSL) --- p.7 / Chapter 2.2.3.1 --- Maturation Theory --- p.7 / Chapter 2.2.3.2 --- Cord Compression Theory --- p.9 / Chapter 2.2.3.3 --- Fetal Hypoxia Theory --- p.10 / Chapter 2.2.4 --- Fetal Effect Of Meconium In Amniotic Cavity --- p.11 / Chapter 2.2.5 --- Meconium Aspiration Syndrome --- p.12 / Chapter 2.2.6 --- Clinical Significance And Limitation Of Studies --- p.13 / Chapter 2.3 --- Purpose Of Study --- p.14 / Chapter CHAPTER 3 --- OXIDATIVE STRESS AND FETAL HYPOXIA --- p.16 / Chapter 3.1 --- OXIDATIVE STRESS --- p.16 / Chapter 3.2 --- FREE RADICALS --- p.16 / Chapter 3.2.1 --- Sources Of Free Radicals --- p.17 / Chapter 3.2.1.1 --- Biological Source Of Free Radicals --- p.17 / Chapter 3.2.1.2 --- Intracellular Source Of Free Radicals --- p.17 / Chapter 3.2.1.3 --- Composition Of Free Radicals And Reactive Oxygen Species --- p.18 / Chapter 3.2.2 --- Cellular Components At Risk From Free Radicals Damage --- p.20 / Chapter 3.2.2.1 --- Proteins --- p.20 / Chapter 3.2.2.2 --- Nucleic Acids And DNA --- p.21 / Chapter 3.2.2.3 --- Membrane Lipids --- p.21 / Chapter 3.2.3 --- Lipid Peroxidation --- p.21 / Chapter 3.2.3.1 --- Chemical Substances Of Membranes --- p.21 / Chapter 3.2.3.2 --- The Reactions Of Lipid Peroxidation --- p.22 / Chapter 3.2.3.3 --- Lipid Peroxidation In Pregnancy --- p.23 / Chapter 3.2.4 --- Protection Against Lipid Peroxidation --- p.24 / Chapter 3.2.5 --- Isoprostanes --- p.26 / Chapter 3.2.5.1 --- Definition --- p.26 / Chapter 3.2.5.2 --- Formation Of Isoprostanes --- p.26 / Chapter 3.2.5.3 --- Metabolism Of Isoprostanes --- p.27 / Chapter 3.2.5.4 --- Biological Characteristics Of Isoprostanes --- p.29 / Chapter 3.2.5.5 --- Isoprostanes As Mediators Of Oxidantive Stress --- p.29 / Chapter 3.3 --- FETAL HYPOXIA --- p.30 / Chapter 3.3.1 --- Fetal Metabolism And Energy Supply --- p.30 / Chapter 3.3.2 --- Free Radical Generation And Fetal Hypoxia-Reoxygenation --- p.33 / Chapter 3.3.3 --- Fetal Hypoxia And Fetal Brain Injury --- p.34 / Chapter 3.3.4 --- Measurement Of Fetal Hypoxia --- p.35 / Chapter 3.3.4.1 --- Acid-Base Balance --- p.35 / Chapter 3.3.4.2 --- Fetal Heart Rate Monitoring --- p.36 / Chapter 3.3.4.3 --- Apgar scores --- p.37 / Chapter 3.3.4.4 --- Pulse Oximetry --- p.37 / Chapter 3.3.4.5 --- Lipid Peroxides --- p.38 / Chapter CHAPTER 4 --- AMNIOINFUSION --- p.40 / Chapter 4.1 --- AMNIOINFUSION --- p.40 / Chapter 4.2 --- AMNIOINFUSION FOR OLIGOHYDRAMNIOS --- p.40 / Chapter 4.3 --- AMNIOINFUSION FOR MECONIUM STAINED LIQUOR --- p.41 / Chapter 4.4 --- PURPOSE OF THE STUDY --- p.42 / Chapter PART 2 --- CLINICAL PROTOCOLS AND MEASUREMENT OF ISOPROSTANES / Chapter CHAPTER 5 --- CLINICAL PROTOCOLS --- p.43 / Chapter 5.1 --- ETHICS --- p.43 / Chapter 5.2 --- CLINICAL PROTOCOLS --- p.43 / Chapter 5.2.1 --- Artificial Rupture Of Membranes (Amniotomy) --- p.43 / Chapter 5.2.2 --- Classification of Meconium Stained Liquor --- p.44 / Chapter 5.2.3 --- Electronic Fetal Heart Rate Monitoring --- p.44 / Chapter 5.2.4 --- Monitoring The Progress of Labour --- p.44 / Chapter 5.2.5 --- Umbilical Cord Blood Gas Analysis --- p.45 / Chapter 5.2.6 --- Apgar Score --- p.45 / Chapter 5.2.7 --- Meconium Aspiration --- p.46 / Chapter 5.2.8 --- Clinical Outcome --- p.46 / Chapter CHAPTER 6 --- MEASUREMENT OF ISOPROSTANES --- p.50 / Chapter 6.1 --- BLOOD PREPARATION --- p.50 / Chapter 6.2 --- REAGENTS --- p.50 / Chapter 6.3 --- GAS CHROMATOGRAPHY AND MASS SPECTROMETRY (GC-MS) --- p.51 / Chapter 6.4 --- PROCEDURES --- p.51 / Chapter 6.5 --- DATA RELIABILITY --- p.53 / Chapter PART 3 --- RESULTS AND DISCUSSION / Chapter CHAPTER 7 --- MECONIUM STAINED LIQUOR (MSL) DURING LABOUR AND NEONATAL CORD BLOOD 8-IS〇-PGF2α CONCENTRATION --- p.54 / Chapter 7.1 --- OBJECTIVE --- p.54 / Chapter 7.2 --- MATERIALS AND METHOD --- p.55 / Chapter 7.3 --- STATISTICAL ANALYSIS --- p.56 / Chapter 7.4 --- RESULTS --- p.57 / Chapter 7.5 --- DISCUSSION --- p.65 / Chapter 7.6 --- CONCLUSION --- p.67 / Chapter CHAPTER 8 --- EVALUATION OF PROPHYLACTIC AMNIOINFUSION FOR INTRAPARTUM MECONIUM STAINED LIQUOR --- p.69 / Chapter 8.1 --- OBJECTIVE --- p.69 / Chapter 8.2 --- MATERIALS AND METHOD --- p.69 / Chapter 8.2.1 --- Study Group: 226}0ب MSL+AI' --- p.69 / Chapter 8.2.2 --- The Procedure Of Amnioinfusion --- p.70 / Chapter 8.2.3 --- Other Study Group --- p.71 / Chapter 8.3 --- STATISTIC ANALYSIS --- p.71 / Chapter 8.4 --- RESULTS --- p.72 / Chapter 8.4.1 --- Comparison Between The 'MSL+AI' And 'MSL-AI' Groups --- p.72 / Chapter 8.4.2 --- Comparison Between 226}0بMSL+AI'And 'Clear Liquor' Groups --- p.74 / Chapter 8.5 --- DISCUSSION --- p.77 / Chapter 8.6 --- CONCLUSION --- p.79 / Chapter CHAPTER 9 --- COMMENTS AND FUTURE RESEARCH --- p.80 / BIBLIOGRAPHY --- p.83

Leung Yee Fong, Vivian. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1997. / Includes bibliographical references (leaves 159-169). / Acknowledgments --- p.i / Legend for figures --- p.ii / Legend for tables --- p.v / List of abbreviations --- p.vii / Abstract --- p.viii / Chapter Ch 1 --- Introduction --- p.1 / Chapter 1.1 --- Embryology --- p.1 / Chapter 1.1.1 --- Embryology of amniotic cavity --- p.1 / Chapter 1.1.2 --- Embryology of kidney and bladder --- p.3 / Chapter Ch 2 --- Background: What is already known about amniotic fluid volume? --- p.7 / Chapter 2.1 --- Normal physiology --- p.7 / Chapter 2.1.1 --- The origin of amniotic fluid: Where does it come from? --- p.8 / Chapter 2.1.2 --- Where does the amniotic fluid go? How reabsorbed? --- p.14 / Chapter 2.1.3 --- How is amniotic fluid volume controlled? --- p.18 / Chapter 2.2 --- Abnormal physiology --- p.26 / Chapter 2.2.1 --- Too much liquor: polyhydramnios --- p.26 / Chapter 2.2.2 --- Too little liquor: oligohydramnios --- p.28 / Chapter 2.2.3 --- Diseases and gender differences that may be related to parity and amniotic fluid volume --- p.30 / Chapter 2.3 --- Techniques of measuring amniotic fluid volume --- p.32 / Chapter 2.3.1 --- History --- p.32 / Chapter 2.3.2 --- Current most popular technique: amniotic fluid index --- p.38 / Chapter 2.4 --- Summary of what is known and not yet known about amniotic fluid volume --- p.48 / Chapter Ch 3 --- Aims of this study --- p.49 / Chapter Ch4 --- Method --- p.50 / Chapter 4.1 --- Equipment --- p.50 / Chapter 4.2 --- Subject selection criteria --- p.50 / Chapter 4.2.1 --- Criteria --- p.50 / Chapter 4.2.2 --- Total number of subjects studied --- p.51 / Chapter 4.2.3 --- Total number of subjects selected fulfilling all criteria --- p.51 / Chapter 4.2.4 --- Subject preparation --- p.52 / Chapter 4.3 --- Technique --- p.53 / Chapter 4.3.1 --- "Standard measurement of BPD， AC, FL and EFW" --- p.53 / Chapter 4.3.2 --- Standard measurement of Doppler --- p.54 / Chapter 4.3.3 --- Amniotic fluid index --- p.55 / Chapter 4.3.4 --- Bladder volume --- p.59 / Chapter 4.3.5 --- Fetal renal pelvis --- p.61 / Chapter 4.3.6 --- Intra-observer error techniques and calculation --- p.63 / Chapter 4.4 --- Techniques used in analysis --- p.65 / Chapter Ch5 --- Results --- p.67 / Chapter 5.1 --- Fetal parameters --- p.68 / Chapter 5.1.1 --- Fetal biparietal diameter (BPD) --- p.68 / Chapter 5.1.2 --- Fetal abdominal circumference (AC) --- p.69 / Chapter 5.1.3 --- Fetal femur length (FL) --- p.70 / Chapter 5.1.4 --- Pulsatility index values of umbilical artery --- p.71 / Chapter 5.1.5 --- Birth weight (BW) --- p.74 / Chapter 5.1.6 --- Estimated fetal weight --- p.76 / Chapter 5.2 --- Amniotic fluid index --- p.79 / Chapter 5.2.1 --- Amniotic fluid index-overall --- p.79 / Chapter 5.2.2 --- Amniotic fluid index-male and female --- p.81 / Chapter 5.2.3 --- The ten segments of amniotic fluid index distribution --- p.83 / Chapter 5.2.4 --- Amniotic fluid index relationship to estimated fetal weight --- p.86 / Chapter 5.2.5 --- Amniotic fluid index with gravidity and parity --- p.89 / Chapter 5.2.6 --- Amniotic fluid index with estimated fetal weight of different parity (best fit line) for both male and female --- p.93 / Chapter 5.3 --- Fetal urinary bladder volume (BV) --- p.96 / Chapter 5.3.1 --- Bladder volume-overall --- p.96 / Chapter 5.3.2 --- Bladder volume-male and female --- p.97 / Chapter 5.3.3 --- Bladder volume with estimated fetal weight- overall --- p.100 / Chapter 5.3.4 --- Bladder volume with estimated fetal weight in both male and female --- p.101 / Chapter 5.3.5 --- Bladder volume with gravidity and parity --- p.103 / Chapter 5.3.6 --- Bladder volume with amniotic fluid index --- p.105 / Chapter 5.4 --- Anteroposterior diameter of the fetal renal pelvis --- p.106 / Chapter 5.5 --- Hydronephrosis index values --- p.107 / Chapter Ch 6 --- Discussion --- p.108 / Chapter 6.1 --- Review of the study --- p.108 / Chapter 6.2 --- Discussion on subject --- p.111 / Chapter 6.2.1 --- Gestational age chosen --- p.111 / Chapter 6.2.2 --- Subject preparation --- p.112 / Chapter 6.3 --- Discussion of method --- p.114 / Chapter 6.3.1 --- Equipment --- p.114 / Chapter 6.3.2 --- Technique --- p.117 / Chapter 6.4 --- Discussion on results --- p.128 / Chapter 6.4.1 --- Normality of population --- p.128 / Chapter 6.4.2 --- Low birth weight/ IUGR in Chinese and Caucasian --- p.129 / Chapter 6.4.3 --- Cut-off points to detect oligohydramnios and polyhydramnios --- p.132 / Chapter 6.4.4 --- Amniotic fluid index-relationship with fetal weight --- p.143 / Chapter 6.4.5 --- Amniotic fluid index-relationship to parity --- p.145 / Chapter 6.4.6 --- "Relationship between gender, estimated fetal weight and amniotic fluid index" --- p.147 / Chapter 6.4.7 --- Parity and cut-off points for oligohydramnios and polyhydramnios --- p.150 / Chapter 6.4.8 --- Relationship of amniotic fluid volume to urinary function --- p.152 / Chapter Ch 7 --- Conclusions --- p.157 / References --- p.159

Tout comme le placenta, les membranes amniotiques humaines sont des organes transitoires mais indispensables au développement fœtal. Parmi les nombreuses fonctions de ces membranes, le contrôle du volume de liquide amniotique est une des plus importantes. Les aquaporines (AQP), canaux aqueux transmembranaires permettant les transferts d’eau, ont déjà été décrites comme fortement impliquées dans ce phénomène. Afin d’éclaircir et d’approfondir leurs implications et leur importance au cours de la grossesse, nous nous sommes intéressé, dans un premier temps, à déterminer l’expression spatio‐temporelle des aquaporines dans les membranes fœtales tout au long de la grossesse, et, dans un second temps, à étudier les aquaporines comme gènes cibles des rétinoïdes. En effet, ces derniers sont des morphogènes impliqués dans le développement embryonnaire et dans la physiologie des annexes embryo‐fœtales et paraissaient être des candidats intéressants pour réguler l’expression des gènes des aquaporines. Nous avons ainsi mis en évidence que, parmi les treize AQPs décrites chez les mammifères, cinq sont exprimées, aussi bien à terme que tout au long de la grossesse, dans les deux feuillets membranaires (le chorion et l’amnion) et à des niveaux d’expression variables en fonction du stade gestationnel et du feuillet membranaire étudié. De plus, nous avons pu proposer un modèle de régulation de l’aquaporine 3 (AQP3) par les rétinoïdes dans les cellules épithéliales amniotiques humaines. Les modulations de l’expression des AQPs 1, 3, 8, 9, 11 tout au long de la grossesse ainsi que la mise en évidence de la régulation de l’AQP3 par les rétinoïdes confirme la nécessité d’une régulation fine de ces gènes au cours de la gestation ; et ce afin de permettre la régulation de l’homéostasie du liquide amniotique, phénomène physiologique essentiel au déroulement harmonieux de la grossesse. Toute altération de cette expression et/ou de cette régulation peut être à l’origine de pathologies du volume amniotique lors de la grossesse, comme l’oligoamnios ou le polyhydramnios. / As the placenta, human amniotic membranes are transitory but essential for the fetal development. Among their numerous functions, the regulation of the amniotic fluid volume is one of the most important. As previously described, this mechanism largely involves transmembrane water channels , the aquaporins (AQPs). In order to clarify and understand their implications and importance during pregnancy, we firstly investigated the spatio‐temporal expression of aquaporins in the fetal membranes throughout pregnancy. In a second time, we studied the aquaporin genes as targets of retinoids. These morphogenetic molecules involved in the fetal annexes and embryonic/fetal development appeared as interesting candidates to regulate aquaporins genes expression in fetal membranes. We have demonstrated that, among the thirteen AQPs described in mammals, five are expressed both at term and throughout pregnancy in both fetal membranes layers (chorion and amnion). Their expression levels vary with the gestational stage and the type of layer. In addition, we were able to propose a model of regulation of aquaporin 3 (AQP3) by retinoids in human amniotic epithelial cells. The modulation of the expression of AQPs 1, 3, 8, 9, 11 throughout pregnancy as well as the demonstration of the AQP3 regulation by retinoids suggests a fine regulation of these genes is necessary during gestation in order to allow the maintenance of amniotic fluid homeostasis, a physiological phenomenon essential to a harmonious pregnancy. Alterations of this expression and/or this regulation could cause diseases of amniotic volume during pregnancy, such as oligohydramnios or polyhydramnios.

The purpose of this study was to explore the behavioral effects of amniotic fluid (AF) and milk in the newborn rat. Previous research has documented behavioral effects in the fetal and neonatal rat. For example, oral exposure to AF and milk reduces the response to chemosensory stimulation in rat fetuses (Korthank & Robinson, 1998) and newborns (Méndez-Gallardo & Robinson, 2010). In addition, some of the behavioral effects of AF and milk are mediated by the endogenous opioid system in the perinatal rat, including modulation of the facial wiping response (Korthank & Robinson, 1998; Méndez-Gallardo & Robinson, 2010), the stretch response induced by milk in the fetal rat (Smotherman & Robinson, 1992b), and the effect of milk as an unconditioned stimulus (US) during associative learning in the fetal rat (Robinson et al., 1993). Taking into account the literature that suggests similarities between AF and milk, this study aimed to evaluate whether transnatal continuity in the behavioral effects of AF and milk could be found and whether mediation by the endogenous opioid system is the underlying mechanism of these effects. To fulfill this purpose, overall behavioral activation, crawling locomotion, oral responses to an artificial nipple, and associative learning were investigated in the newborn rat. Results showed that, (a) oral exposure to AF resulted in higher levels of behavioral activation than oral exposure to milk, (b) exposure to the odor of AF or milk did not produce significant behavioral activation, although the odor of milk seemed to evoke higher levels of behavioral activity than exposure to the odor of AF, (c) both AF and milk odor elicited crawling locomotion, (d) odor of AF or milk did not promote oral grasping of an artificial nipple, but promoted mouthing responses and distinctive movements of the forepaws, (e) contingent presentations of an artificial nipple as the conditioned stimulus (CS), with AF or milk as the US, promoted mouthing responses during reexposure to the CS, but facial wiping after CS reexposure was not modified as a result of conditioning, and (f) mediation of the opioid system was evident only during hindlimb activity after oral exposure to AF or milk and during mouthing responses to the CS after associative learning. These findings suggest that oral exposure to AF or milk consistently evoke opioid responses in the neonatal rat, but exposure to the odor of AF or milk alone does not. Through postnatal testing and the direct comparison of the behavioral effects of AF (a feature of the prenatal environment) with milk (a feature of the postnatal environment), this study contributes to a better understanding of mechanisms that promote behavioral continuity before and after birth.

Brain injury, either surgically induced or as a result of trauma or stroke, is one of the leading causes of death and disability worldwide. Since transplantable stem cell sources are showing a great deal of promise and are actively being pursued to provide neuroprotection post-injury, in this body of work, we set out to characterize and examine the therapeutic potential of amniotic fluid derived (AF) cells as a potential cell source for cell-based therapies in mediating neuroprotection post-injury. Despite their heterogeneity, we found that AF cells are mainly epithelial in origin and express various genes involved in stem cell maintenance and neural commitment. A very small subset of AF cells also express pluripotency markers OCT4a, SOX2 and NANOG, which can be enriched for by single cell cloning. SOX2 positive clones have the capacity to give rise to a neuronal phenotype, in neural induction conditions, which can be used to examine the neural differentiation capabilities of AF cells. Subsequently, we examined the ability of AF cells to mediate a neuroprotective effect in a surgically induced brain injury model through gap junctional-mediated direct cell-cell communication and as a vehicle for GDNF delivery post-injury. AF cells express high levels of CX43 and are able to establish functional gap junctional intercellular communication (GJIC) with cortical astrocytes. We report an induction of Cx43 expression in astrocytes following injury and demonstrate, for the first time, CX43 expression at the interface between implanted AF cells and host astrocytes. In an effort to boost host endogenous neuroprotective mechanisms post-injury, via neurotrophic factor delivery, we engineered AF cells to secrete GDNF (AF-GDNF). GDNF pre-treatment significantly increased AF cell and cortical neuron survival rates following exposure to hydrogen peroxide. AF-GDNF cells, seeded on polyglycolic acid (PGA) scaffolds, survived longer in serum-free conditions and continued to secrete GDNF post-implantation activating the MAPK/ERK signaling pathway in host neural cells in the peri-lesion area. Despite some promising trends, we did not observe significant behavioural improvements following AF-GDNF/PGA implantation nor reduced lesion volume during the 7 day time-frame. In conclusion, through GJIC with cortical astrocytes and delivery of exogenous neurotrophic factors, AF cells hold great promise in mediating neuroprotection post-injury.