• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 318
  • 182
  • 77
  • 30
  • 27
  • 12
  • 11
  • 9
  • 7
  • 5
  • 4
  • 3
  • 3
  • 2
  • 2
  • Tagged with
  • 798
  • 141
  • 85
  • 64
  • 59
  • 57
  • 44
  • 42
  • 42
  • 41
  • 40
  • 34
  • 34
  • 32
  • 32
  • 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.
31

The Transfer of Ethyl Glucuronide in the Dually Perfused Ex Vivo Placental Perfusion Model: Implications for Alcohol Screening during Pregnancy

Matlow, Jeremy 22 November 2012 (has links)
Alcohol consumption during pregnancy can lead to Fetal Alcohol Spectrum Disorder, and because maternal self-reports are often unreliable, a biomarker of alcohol use during pregnancy is needed to accurately determine fetal exposure. Ethyl glucuronide (EtG) is a direct metabolite of ethanol that has been detected in the meconium of infants born to mothers who consumed alcohol during pregnancy. In the current study, a method was developed and validated for EtG detection in placental perfusate and tissue using gas chromatography-mass spectrometry. Subsequently, the ex vivo human placental perfusion model was used to investigate whether EtG crosses the human placenta. The validated GC-MS method showed sufficient sensitivity in detecting EtG in placental perfusate and tissue. EtG crossed the placenta slowly and transfer was incomplete after 3 hours of perfusion. EtG appears to cross the human placenta and, hence, to represent both maternal and fetal exposure to alcohol.
32

The Transfer of Ethyl Glucuronide in the Dually Perfused Ex Vivo Placental Perfusion Model: Implications for Alcohol Screening during Pregnancy

Matlow, Jeremy 22 November 2012 (has links)
Alcohol consumption during pregnancy can lead to Fetal Alcohol Spectrum Disorder, and because maternal self-reports are often unreliable, a biomarker of alcohol use during pregnancy is needed to accurately determine fetal exposure. Ethyl glucuronide (EtG) is a direct metabolite of ethanol that has been detected in the meconium of infants born to mothers who consumed alcohol during pregnancy. In the current study, a method was developed and validated for EtG detection in placental perfusate and tissue using gas chromatography-mass spectrometry. Subsequently, the ex vivo human placental perfusion model was used to investigate whether EtG crosses the human placenta. The validated GC-MS method showed sufficient sensitivity in detecting EtG in placental perfusate and tissue. EtG crossed the placenta slowly and transfer was incomplete after 3 hours of perfusion. EtG appears to cross the human placenta and, hence, to represent both maternal and fetal exposure to alcohol.
33

The role of ovine betaretroviruses in uteroplacental function

Dunlap, Kathrin Anson 02 June 2009 (has links)
Endogenous retroviruses (ERVs) account for a substantial portion of the genetic pool of every animal species (e.g. ~ 8% of the human genome). Despite their overwhelming abundance in nature, many questions on the basic biology of ERVs are unanswered. Sheep harbor approximately 20 copies of endogenous betaretroviruses (enJSRVs), which are related to an exogenous oncogenic virus, Jaagsiekte sheep retrovirus (JSRV). Therefore, they are an attractive model for investigation of the potential beneficial roles of ERVs in reproductive biology. Studies were conducted to determine: 1) expression of enJSRVs envelope (env) and HYAL2 mRNAs in the ovine uterus and conceptus (embryo/fetus and extraembryonic membranes) throughout gestation; 2) regulation of enJSRVs expression by progesterone; and 3) the role of enJSRVs in regulating peri-implantation placental growth and differentiation. Study One determined the localization of enJSRVs env and HYAL2 mRNAs throughout gestation. Results demonstrate that alterations in expression of enJSRVs and HYAL2 in the sheep uterus and placenta suggest the probability of a variety of physiological roles in implantation and placentation. Partial sequencing of the transcriptionally active enJSRVs from ovine uteroplacental tissues revealed expression of multiple enJSRV loci. Study Two assessed the influence of progesterone, interferon tau, and pregnancy stage on enJSRVs expression, as an effort to understand factors that may regulate enJSRVs. Results of this study support the hypothesis that expression of enJSRVs is modulated by progesterone, but not IFNτ in vivo. Study Three provides for enJSRVs regulating trophectoderm growth and differentiation in the peri-implantation conceptus. Blocking conceptus enJSRVs Env expression compromised pregnancy by retarding trophoblast outgrowth and differentiation. Inhibition of enJSRVs Env in vitro also reduced proliferation of mononuclear trophectoderm cells. Consequently, these results demonstrate that enJSRVs Env regulates trophectoderm growth and differentiation in the ovine conceptus, strongly supporting the biological significance of ERVs in placental evolution and animal reproduction Collectively, these studies illustrate that enJSRVs play an integral role in success of pregnancy. While the definitive roles of the enJSRVs have not yet been elucidated, it is evident that enJSRVs are an important component of the ovine genome and that they influence recognition and maintenance of pregnancy and placental formation.
34

VEGF in the Placenta and Maternal Circulation and Organs during Pregnancy in Mice

Minhas, Abhijeet 27 November 2013 (has links)
Whether vascular endothelial growth factor A (VEGF) plays an augmented role during pregnancy is unknown. In this thesis expression of VEGF in the placenta, maternal circulation and organs in mice was examined using qRT-PCR, LacZ expression, and/or ELISAs. Normal pregnancies and pregnancies with transgenic conceptuses that over-express VEGF in the placenta were examined. In normal pregnancies, VEGF120/164 levels in the ovary increased in parallel with that of the maternal circulation. In pregnancies where the placenta over-expressed VEGF, maternal circulating VEGF120/164 levels decreased and so did levels in the maternal ovary. Surprisingly, VEGF protein levels (per mg of total protein) decreased in the growing, highly vascular placenta during pregnancy. In conclusion this thesis provides evidence for an important ovarian source of maternal circulating VEGF120/164 during pregnancy.
35

VEGF in the Placenta and Maternal Circulation and Organs during Pregnancy in Mice

Minhas, Abhijeet 27 November 2013 (has links)
Whether vascular endothelial growth factor A (VEGF) plays an augmented role during pregnancy is unknown. In this thesis expression of VEGF in the placenta, maternal circulation and organs in mice was examined using qRT-PCR, LacZ expression, and/or ELISAs. Normal pregnancies and pregnancies with transgenic conceptuses that over-express VEGF in the placenta were examined. In normal pregnancies, VEGF120/164 levels in the ovary increased in parallel with that of the maternal circulation. In pregnancies where the placenta over-expressed VEGF, maternal circulating VEGF120/164 levels decreased and so did levels in the maternal ovary. Surprisingly, VEGF protein levels (per mg of total protein) decreased in the growing, highly vascular placenta during pregnancy. In conclusion this thesis provides evidence for an important ovarian source of maternal circulating VEGF120/164 during pregnancy.
36

Placental pathology correlation to fetal and neonatal diagnostic outcomes in a cohort of infants admitted in a newborn high risk follow-up program

Schanbacher, David 13 January 2015 (has links)
This study is designed to investigate the nature of pathologically significant placentas and their corresponding fetal and neonatal outcomes in term infants. We aim to examine the correlation between specific placental pathologies and neonatal clinical conditions, including brain injury, requiring admission to a neonatal care unit and subsequent follow-up in our High Risk Newborn Follow-up Program (HRFU). A retrospective cohort study was conducted through review of maternal and neonatal reports. Overall 48 neonates had placentas submitted for examination. Sixty-one percent of placentas in the HRFU group and 62% of placentas in the non-HRFU group had findings consistent with ischemic changes, meconium staining and calcifications. Three infants had hypoxic ischemic encephalopathy. This study found no difference in placental pathology between non-HRFU infants and infants enrolled in the HRFU Program. This raises questions and warrants further study on the efficacy for placental submission as a predictive measure for neonatal outcomes.
37

DREAM-mediated Regulation of GCM1 in the Human Placental Trophoblast

Baczyk, Dorota 05 April 2010 (has links)
The trophoblast transcription factor glial cell missing-1 (GCM1) regulates asymmetric division of placental cytotrophoblast to form the differentiated syncytiotrophoblast. Reduced GCM1 expression is a key feature of the hypertensive disorder preeclampsia. In-silico techniques identified a novel calcium-dependent transcriptional repressor – DREAM as a regulatory candidate for GCM1. The overall objective of this thesis was to determine if DREAM regulates GCM1 expression and therefore villous trophoblast turnover. siRNA-mediated DREAM silencing in both BeWo cells and floating villous explants significantly upregulated GCM1 causing reduced cytotrophoblast proliferation. Calcium-dependency was demonstrated in both BeWo cells and floating villous explants by contrasting the effects of ionomycin and nimodipine. A direct interaction between DREAM and the GCM1 promoter was demonstrated using EMSA and ChIP assay. DREAM is a negative upstream regulator of GCM1 expression in human placenta that participates in calcium-dependent trophoblast differentiation.
38

DREAM-mediated Regulation of GCM1 in the Human Placental Trophoblast

Baczyk, Dorota 05 April 2010 (has links)
The trophoblast transcription factor glial cell missing-1 (GCM1) regulates asymmetric division of placental cytotrophoblast to form the differentiated syncytiotrophoblast. Reduced GCM1 expression is a key feature of the hypertensive disorder preeclampsia. In-silico techniques identified a novel calcium-dependent transcriptional repressor – DREAM as a regulatory candidate for GCM1. The overall objective of this thesis was to determine if DREAM regulates GCM1 expression and therefore villous trophoblast turnover. siRNA-mediated DREAM silencing in both BeWo cells and floating villous explants significantly upregulated GCM1 causing reduced cytotrophoblast proliferation. Calcium-dependency was demonstrated in both BeWo cells and floating villous explants by contrasting the effects of ionomycin and nimodipine. A direct interaction between DREAM and the GCM1 promoter was demonstrated using EMSA and ChIP assay. DREAM is a negative upstream regulator of GCM1 expression in human placenta that participates in calcium-dependent trophoblast differentiation.
39

Morphogenesis of the fetal membranes and placenta of the tree shrews, family Tupaiidae

Luckett, W. Patrick January 1967 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1967. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
40

Morphology of the uterus and placenta of the impala, Aepyceros melampus

Kennan, Kathleen Day, January 1966 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1966. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Page generated in 0.0595 seconds