Thèses : « Fetal cell »

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Götherström, Cecilia. « Characterisation of human fetal mesenchymal stem cells / ». Stockholm, 2004. http://diss.kib.ki.se/2004/91-7140-139-3/.

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Weinhaus, Anthony James. « Physiology of the fetal B-cell ». Thesis, The University of Sydney, 1994. https://hdl.handle.net/2123/26826.

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The use of islets isolated from the human fetal pancreas may provide a source of transplantable tissue with the potential to reverse diabetes. Further research is required before there is enough knowledge of the function of these islets to enable their successful transplantation to humans. Chapter 1 Experiments on fetal pancreas are limited by the paucity and irregularity of the supply of donor tissue. Therefore, a human fetal pancreatic B—cell line would be of considerable use in the better understanding of this potential source of transplantable tissue. In chapter 1 of this thesis, success in isolating an immortalised fetal lung fibroblast cell line by SV—40 viral infection is described. Satisfied with this procedure, attempts were then made to isolate a human fetal pancreatic .cell line by infection with SV—4O virus and transfection with plasmid vectors containing SV—4O genes. Although unsuccessful in isolating an immortalised cell line, a protocol was established for the transfection of human fetal endocrine cells in the future. Chapter 2 It has been well established that the fetal rat and human pancreatic islet B—cell secretes insulin poorly in response to glucose compared to that from adult B—cells. However, the cellular mechanism for this is unknown. In chapter 2, microfluorometric studies are described using the intracellular fluorescent dye fura—Z to measure changes in the cytoplasmic free Ca2+ concentration in fetal, neonatal and adult rat B—cells to determine the ability of glucose and other insulin secretagogues to cause an increase in [Ca2+]i believed to be the trigger for insulin secretion. The fetal B-cell responded to various insulin secretagogues, but not glucose, with an increase in [Ca2+].l and insulin release. The immature insulin secretory response to glucose by the fetal B—cell is, therefore, due to its inability to translate glucose stimulation into an increase in [Ca2+]i required for exocytosis of insulin. Chapter 3 The protocols used in experiments conducted on rat fetal B-cells were used for experiments on human fetal B—cells described in chapter 3 to determine the ability of glucose and other insulin secretogogues to cause an increase in [Ca“1i. In this study, mid-gestation fetal human and late—gestation fetal porcine islet—like cell clusters, as well as adult human islets and the only available human B—cell line, the adult insulinoma cell line HP—62, were studied using microfluorometric methods. Both the mid—gestation human fetal B-cell and the late—gestation porcine fetal B—cell possesses the complete mechanism required to translate stimulation by secretagogues other than glucose into an increase in [Ca2+]i required for secretion of insulin. The end-stage of the signal transduction pathway in these fetal B—cell is, therefore, mature. The immature secretory response to glucose must, therefore, be located at some other step of glucose-induced stimulation such as glucose transport, glucose metabolism or in the linkage between glycolysis and mitochondrial metabolism. Chapter 4 The amino acid arginine is known to cause insulin release from glucose—insensitive human and rat fetal B—cells, as well as from rat adult perfused pancreas, pancreatic explants and perifused islets. Exposure of rat and human fetal B—cells to arginine was found in the studies described in chapter 2 and 3 to cause an increase in [Ca“]r The cellular mechanisms involved in the B—cell response to arginine are not well described. Experiments described in chapter 4 were conducted to identify the mechanisms involved in arginine-induced stimulation of the B—cell using an insulinoma cell line (NIT—l). As in the studies described. in Chapters 2 and 3, the ratiometric fluorescent probe of Ca”) fura—Z, was used to directly monitor changes in [Ca”1i. The effects of L—arginine, and its analogues which do not produce nitric oxide were investigated to characterise the mechanisms of arginine—induced B—cell stimulation and determine if nitric oxide production plays a role in this stimulation. The data demonstrate that L—arginine, and its analogues, caused similar increases in [Ca2+]i and insulin release. This suggests that nitric oxide production has no role in the arginine—induced increase in [Ca2+]i in the NIT—l cell. The increase in [Ca2+]i is due to a combination of the direct depolarisation of the membrane due to the electrogenic effect of arginine plus an effect due to the metabolism of the amino acid.

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Cowan, Gillian. « Fetal germ cell differentiation and the impact of the somatic cells ». Thesis, University of Edinburgh, 2009. http://hdl.handle.net/1842/4164.

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Specification of a germ cell lineage and appropriate maturation are essential for the transfer of genetic information from one generation to the next. Germ cells form from pluripotent precursor cells that migrate into the gonadal ridge and undergo commitment to either the female or male lineage. In the fetal ovary, germ cells enter meiotic prophase I, then arrest at the diplotene stage; in the testis germ cells do not begin meiosis until puberty. Abnormal differentiation of germ cells can result in malignant transformation. Somatic cells play a key role in modulating the developmental fate of the germ cells. Research into germ cell development during fetal life has almost exclusively focused on studies in rodents, but we, and others, have reported several fundamental differences in the expression of germ cell specific markers in the human compared with the mouse. The studies described in this thesis have investigated germ cell-specific gene expression and the possible impact of the somatic cells during development. This was achieved by studying human fetal gonads obtained during the 1st and 2nd trimesters of pregnancy and through the use of both wild-type and mutant mouse ES cell lines. Studies on germ cells in the human fetal testis have extended the findings of others, and confirmed that germ cell populations at different stages of maturation co-exist in the human fetal testis, a situation that is in contrast to that in rodents. For example expression of M2A and AP2γ was restricted to the OCT4-positive gonocyte population, while VASA and NANOS1 were localised exclusively to the to the OCT4-negative prespermatogonia. DAZL was expressed in both populations. Analysis also revealed that both the gonocyte and prespermatogonial populations proliferate throughout the 2nd trimester. Recent studies have implicated retinoic acid (RA) in the control of meiotic entry in germ cells of the fetal mouse ovary. In this study we demonstrated for the first time that two genes implicated in the action of RA in mouse gonad, STRA8 and NANOS2, are also expressed in a similar sexspecific- manner in the human fetal gonads, and that the RA receptors are present in both somatic and germ cells suggesting that RA may regulate germ cell function in the human as well as the mouse. However, whilst the mesonephros appears to be the primary site of RA synthesis in the mouse our initial studies indicate that in the human the gonad itself may be a more likely site of RA biosynthesis. In the fetal mouse testis, RA is degraded by the enzyme Cyp26b1 present in the somatic cells and germ cells do not enter meiosis, our novel findings suggest that CYP26B1 is more abundant in the human fetal ovary than the testis, suggesting that meiotic entry may be controlled by an alternative signalling pathway in the human. One of the methods that can aid our understanding of somatic cell gene expression in the gonad is in vitro culture. To date, there have been no published reports of the successful in vitro culture of somatic cells from the human fetal testis. In the current study, populations of human somatic cells were dissociated and maintained in vitro and characterised. Analysis demonstrated that cells expressing mRNAs characteristic of Sertoli cells, Leydig cells and peritubular myoid (PTM) cells were present initially, but long-term culture resulted in downregulation in expression of mRNAs specific for Sertoli cells and Leydig cells, suggesting that these cells either failed to survive or underwent alterations to their phenotype. In contrast PTM/fibroblast cells proliferated in vitro and initially maintained androgen receptor expression. These cultures therefore hold promise for studies into the signalling or cell-cell interactions in testicular somatic cells especially those relevant to the PTM population. Several studies have claimed differentiation of putative germ cells from ES cells. In the current study, analysis of mouse ES cell lines has expanded on results showing that ES cells and early germ cells express a number of genes in common. Kit signalling was shown to be important for ES cell survival as they differentiate although expression of Kit was heterogeneous. We also demonstrated that ES cells that did not express Kit displayed a decreased expression of the early germ cell genes Blimp1, Fragilis and Stella, implicating Kit signalling in the control of germ cell-associated gene expression in ES cells. This may be important to future studies optimising germ cell derivation from ES cells. In conclusion, this study has demonstrated important differences in protein expression patterns in germ cells of the human fetal testis compared to the mouse, and has raised questions about whether the proposed mechanism controlling meiotic entry of germ cells in the mouse can be applied to the human. The establishment of a system for culturing human fetal gonadal somatic cells may lead to further understanding of gene expression and development in the human fetal testis, and data suggest that the Kit/Kitl signalling system may influence germ cell gene expression in mouse ES cells.

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Li, Qinggang. « In vitro regulation of fetal bovine erythropoiesis ». Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=42078.

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Fetal bovine serum (FBS) is one of the most important supplements for cell culture, and is a rich source of both defined and unknown factors required for proper cell growth. A serum-free bioassay system was developed to facilitate the purification and characterization of the heparin-binding growth factors in FBS. Three factors with different effects on erythropoiesis were isolated and identified with the combination of several chromatographic techniques. An 8 kd heparin-binding peptide which stimulated thymidine incorporation into fetal erythroid cells had an N-terminal sequence identical to insulin-like growth factor (IGF II). The growth promoting effect of this peptide was potentiated by heparin in culture. It was also found that the relative affinity of IGFs was in the order of IGF II $>$ IGF I $>$ insulin. The second heparin-binding erythroid regulating factor isolated was a 46 kd protein. The N-terminal sequence of this protein was identical to that of apolipoprotein H (Apo H). It inhibited thymidine incorporation into fetal erythroid cells with an ED$ sb{50}$ of 36 nM. A 100% inhibition of thymidine incorporation and a 40% decrease in cell numbers in culture were observed at 840 nM. The third factor identified was an 11 kd peptide with an N-terminal sequence similar to C4a, a fragment of complement C4. This peptide was a potent cytotoxic agent and was not species-specific, lysing not only bovine fetal erythroid cells, but also human adult red blood cells at very low concentrations.
A clonal assay system for bovine fetal liver cells was developed to further characterize the erythropoietic effects of IGF II, the most important of the isolated factors. It was found that bovine fetal erythroid colonies could not be developed at low concentrations of FBS, unless they were grown over stromal cells. Bovine fetal liver stromal cell lines could support erythroid growth through secreting soluble factor(s) and by direct contact to erythroid cells. It was clear that IGFs stimulated erythropoiesis in this system.

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Saleh, A. W. « Modulation of fetal hemoglobin in sickle cell anemia ». Maastricht : Maastricht : Universiteit Maastricht ; University Library, Maastricht University [Host], 1998. http://arno.unimaas.nl/show.cgi?fid=8498.

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Maciaczyk, Jaroslaw. « Human fetal neural precursor cells : a putative cell source for neurorestorative strategies ». [S.l. : s.n.], 2005. http://nbn-resolving.de/urn:nbn:de:bsz:25-opus-57885.

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Ditadi, Andrea. « Cell therapy approach for hematopoietic diseases using fetal cells issued from amniotic fluid ». Paris 5, 2008. http://www.theses.fr/2008PA05T036.

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Dans la présente étude, nous avons étudié la possibilité de différencier les cellules souches du liquide amniotique humain (hAFSC) et murin (mAFSC) vers la voie hématopoïétique à la fois in vitro et in vivo. Nous avons de manière reproductible réalisé une différenciation érythroïde par culture des hAFSCs en corps embryoïdes (EB). Plus de 70% des cellules constituant les EB coexprimaient des marqueurs erythroïdes. De plus, 3 mois après l'injection de hAFSC à des souris NOD/SCID irradiées, nous avons pu détecter dans la rate et la moelle osseuse des receveurs des érythrocytes humains. Nous avons ainsi comparé le potentiel hématopoïétique des mAFKL, des mAmKL aux KL issues du foie foetal (mFLKL), qui constituent la source principale de cellules souches hématopoïétiques à ce stade de développement. In vivo, nous avons retrouvé dans le sang de souris déficientes pour RAG1, des cellules appartenant aux trois lignées hématopoïétiques (lymphoïde, erythroïdes et myéloïdes) 4 semaines seulement après la greffe de mAFKL et mAmKL. Analysées quatre mois plus tard, les souris greffées présentent des lymphocytes, des érythrocytes et des cellules myéloïdes provenant des mAFKL et mAmKL dans tous les organes hématopoïétiques. Le succès de transplantations secondaires a confirmé que les mAFKL et mAmKL comprennent des progéniteurs hématopoïétiques capables d'auto-renouvellement, ce qui correspond à la définition d'une cellule souche hématopoïétique
In the present study we investigated the possibility of differentiating AFS cells towards the hematopoietic pathway. We achieved a reproducible erythroid differentiation by culturing hAFSCs as embryoid bodies (EBs) under serum free conditions with haematopoietic cytokines. Furthermore, human erythrocytes (human CD235a) were isolated from bone marrow and spleen of sublethally irradiated NOD/SCID mice at 3 months after the injection of hAFSCs. We compared the hematopoietic potential of mAFKL and mAmKL to Fetal Liver KL, the main source of fetal HSC. When cultivated immediatly after their sorting, freshly isolated murine AFKL and AmKL cells gave rise to all the different hematopoietic lineages both in vitro and in vivo. Experiments with freshly isolated hAFKL gave good results in the in vitro assays being able to give rise to erythroid, myeloid and lymphoid lineages, but failed to reconstitute the hematopoietic system in irradiated NOD/SCID mice, probably due to the poor amount of cells injected. This is the first report demonstrating that AFKL and AmKL do have an haematopoietic potential, supporting the idea that AF and Am may be an excellent source for therapeutic application

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Huygens, Ariane. « Fetal T cell response to human congenital cytomegalovirus infection ». Doctoral thesis, Universite Libre de Bruxelles, 2013. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209450.

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Les nouveau-nés et les jeunes enfants ont une susceptibilité plus élevée aux infections par rapport aux enfants plus âgés et aux adultes. Cette caractéristique est en partie attribuée à l’immaturité de leur système immunitaire qui est associée à une capacité limitée à développer des réponses immunitaires à médiation cellulaire. L’infection par le cytomégalovirus (HCMV) est la cause la plus fréquente d’infection congénitale chez l’Homme et une cause majeure de surdité et de retard mental. En Belgique, le dépistage anténatal de l’infection primaire par le HCMV chez les femmes enceintes offre l’opportunité d’étudier les réponses immunitaires du foetus à ce virus et de les comparer à celles de leur maman.

Les lymphocytes T CD4+ Th1 et les lymphocytes T CD8+ cytotoxiques jouent un rôle crucial dans le contrôle des pathogènes intracellulaires dont le HCMV fait partie. La littérature montre une capacité limitée des enfants congénitalement infectés par le HCMV à développer des réponses T CD4+ spécifiques du HCMV. En contraste, des réponses de lymphocytes T CD8+ spécifiques du HCMV ont été rapportées chez des enfants infectés in utero, mais ces réponses n’ont pas été comparées en détails à celles de l’adulte. De plus, notre connaissance des réponses T spécifiques du HCMV durant l’infection primaire par ce virus est limitée. Des études antérieures ont rapporté un défaut de prolifération et de production d’IL-2 des lymphocytes T spécifiques du HCMV chez des adultes avec durant la phase primaire de l’infection, mais les mécanismes restent non-élucidés.

Nous avons caractérisé les réponses de lymphocytes T CD4+ et CD8+ spécifiques du HCMV provenant du sang de cordon de nouveau-nés congénitalement infectés par le HCMV, et nous avons comparé ces réponses à celles de leurs mamans diagnostiquées avec une infection primaire par le HCMV durant la grossesse. En plus, nous avons comparé les réponses T CD4+ et CD8+ de ces mamans à celles d’adultes infectés chroniquement par le virus. Chez les nouveau-nés, nous avons démontré que des lymphocytes T CD4+ de sang de cordon exprimant un phénotype de différentiation spécifique du HCMV (CD27-CD28-) ainsi qu’un phénotype Th1 similaire à celui des cellules maternelles étaient induits in utero lors de l’infection congénitale par le HCMV. De plus, la détection d’expansions oligoclonales suggérait fortement une expansion antigène-spécifique de ces cellules. Cependant, les T CD4+ de nouveau-nés présentaient une capacité fortement réduite à produire des cytokines anti-virales (IFN-γ, TNF-α et MIP-1β) en réponse à une stimulation ex vivo avec les antigènes du HCMV, par rapport aux cellules maternelles. Les lymphocytes T (CD27-CD28-) CD4+ de nouveau-nés produisaient également des niveaux plus bas de cytokines antivirales en réponse à des stimulations polyclonales avec l’anti-CD3 et la PMA/ionomycine, suggérant des altérations en amont et en aval de la voie de signalisation du TCR. Nos résultats suggèrent que ces altérations pourraient impliquer la diminution de l’expression de molécules impliquées dans cette voie de signalisation. De la même manière, nous

avons montré que chez le nouveau-né, la fonction des T CD8+ spécifiques du HCMV était altérée par rapport à celle de l’adulte. Nous avons observé des proportions similaires de T CD8+ (CD27-CD28-) chez les nouveau-nés et les adultes. De plus, l’analyse du répertoire du TCR Vβ de ces cellules par séquençage haut-débit a révélé une capacité similaire à générer un répertoire T diversifié dans les deux groupes. Comme rapporté précédemment, nous avons détecté des fréquences similaires de lymphocytes T CD8+ spécifiques pour l’antigène immunodominant pp65. Cependant, lorsque les stimulations ont été étendues à d’autres antigènes du HCMV, nous avons observé que le répertoire antigénique reconnu par ces cellules était significativement réduit chez les nouveau-nés, en association avec une diminution de la polyfonctionalité et de la production de cytokines par cellule.

Nous avons également montré que, dans une moindre mesure, la fonction des lymphocytes T spécifiques du HCMV était diminuée durant l’infection primaire chez l’adulte. Comme reporté précédemment, les T CD4+ spécifiques du HCMV proliféraient moins et produisaient moins d’IL-2 par rapport à des individus dans la phase chronique de l’infection. Ce défaut de production d’IL-2 affectait à la fois les populations de cellules CD28+ et CD28-, montrant que l’accumulation de lymphocytes T CD4+ ayant perdu l’expression de la molécule CD28 (un signal de co-stimulation important pour la production d’IL-2) est seulement un des facteurs contribuant à la diminution de la production d’IL-2 par les cellules spécifiques du HCMV. En accord avec cette observation, nous avons montré une diminution de la production par cellule d’IFN-γ et de TNF-α touchant également à la fois les populations de T CD4+ CD28+ et CD28- durant la phase primaire de l’infection, un défaut associé avec une avidité fonctionnelle diminuée de ces cellules. De la même manière, la polyfonctionalité et la production de cytokines par cellule des lymphocytes T CD8+ spécifiques du HCMV étaient également diminuées chez les adultes durant la phase d’infection primaire.

En résumé, nos résultats montrent que la fonction des lymphocytes T spécifiques du HCMV de nouveau-nés et d’adultes est altérée durant l’infection primaire par rapport à des individus infectés chroniquement par le virus. Nous montrons que cette régulation fonctionnelle ressemble à l’exhaustion fonctionnelle des lymphocytes T observée durant les infections virales chroniques associées à des charges virales élevées. L’infection primaire par le HCMV est caractérisée par une réplication virale intense qui dure pendant plusieurs mois suivant l’infection. Nous émettons l’hypothèse que les hauts taux de réplication virale observés durant l’infection congénitale et chez l’adulte durant l’infection primaire par le HCMV pourraient interférer avec certaines fonctions des lymphocytes T./Neonates and young infants have a higher susceptibility to infections compared to older infants or adults. This feature is in part attributed to the immaturity of their immune system associated with a limited capacity to mount cellular-mediated immune responses. Congenital human cytomegalovirus (HCMV) infection is the most common cause of congenital infection worldwide and a major cause of hearing loss and mental retardation. In Belgium, antenatal screening of pregnant women for primary HCMV infection offers an opportunity to study neonatal immune responses to the virus and to compare them to those of their mother.

T lymphocytes are major players of the immune system. In particular, Th1 CD4+ T cells and CD8+ cytotoxic T cells play a crucial role in the control of intracellular pathogens, including HCMV infection. Previous literature has reported a limited capacity of infants born with congenital HCMV infection to mount HCMV-specific CD4+ T cell responses. In contrast, fetal antigen-specific CD8+ T cell responses have been reported following in utero HCMV infection, but these responses have not been compared in detail to those of adults with primary infection. In addition, our knowledge regarding adult HCMV-specific T cell responses during primary HCMV infection is limited. Previous studies have reported defective T cell proliferation and IL-2 production in adults with primary HCMV infection, showing that some of the T cell functions are altered during primary infection.

In this study, we have characterized neonatal HCMV-specific CD4+ and CD8+ T cell responses from the cord blood of newborns with congenital HCMV infection, and we have compared these responses to that of their mothers diagnosed with primary HCMV infection during pregnancy. Also, we compared CD4+ and CD8+ T cell responses of adults with primary HCMV infection to that of adults with chronic infection.

In newborns, it was not known if the defective CD4+ T cell responses could be attributed to the absence of HCMV-specific cells or to the induction of dysfunctional cells. We demonstrate that neonatal CD4+ T cells with a differentiation phenotype typical of HCMV infection (CD27-CD28-) and expressing a Th1 phenotype similar to that of maternal cells can differentiate in utero following HCMV infection. In addition, the detection of oligoclonal expansions by spectratyping and flow cytometry analyses strongly suggests antigen-specific responses. However, neonatal CD4+ T cells were markedly less able to produce antiviral cytokines (IFN-γ, TNF-α and MIP-1β) following ex vivo stimulation with HCMV antigens, compared to maternal cells. Also, neonatal CD27-CD28- CD4+ T cells produce lower levels of antiviral cytokines in response to polyclonal stimulations with anti-CD3 and PMA/ionomycin, suggesting alterations up-stream and down-stream of the TCR signaling pathway. Our results suggest that these alterations could involve the down-regulation of the expression of molecules that are part of the TCR signaling pathway. Similarly, we show that the function of

neonatal HCMV-specific CD8+ T cells is impaired compared to adults. Similar proportions of (CD27-CD28-) CD8+ T cells, typical of HCMV infection, were detected in newborns and adults. Analysis of the TCR Vβ repertoire of neonatal and maternal (CD27-CD28-) CD8+ T cells by high-throughput sequencing revealed a similar capacity to generate a diverse clonal repertoire. As previously reported, we detected similar frequencies of HCMV-specific CD8+ T cells specific for the immunodominant viral antigen pp65. However, when extending ex vivo stimulations to other HCMV antigens, we observed that the antigenic repertoire recognized by these cells was significantly reduced in newborns. In addition, neonatal CD8+ T cells had a reduced polyfunctionality and per cell cytokine production.

To a lower extent, the function of adult HCMV-specific T cells was also impaired during primary infection. As previously reported, maternal HCMV-specific CD4+ T cells were markedly less able to produce IL-2 and to proliferate compared to individuals in the chronic stage of the disease. Both CD28+ and CD28- T cell subsets produced decreased levels of IL-2. This observation shows that the accumulation of HCMV-specific CD4+ T cells having lost the expression of the CD28 molecule (an important co-stimulatory signal for IL-2 production) during primary infection is only one of the factors contributing to the decreased IL-2 production. Accordingly, both CD28+ and CD28- CD4+ T cell subsets had a decreased per cell production of IFN-γ and TNF-α during primary HCMV infection. This defect was associated with a lower functional avidity of these cells. Similarly, the polyfunctionality and per cell cytokine production of adult HCMV-specific CD8+ T cells was also impaired compared to adults with chronic infection.

Altogether, our results show that adult and neonatal HCMV-specific T cell responses are impaired during primary infection, compared to individuals with chronic infection. We show that this functional regulation resembles that of functional T cell exhaustion observed during chronic viral infections that are associated with high levels of viral replication. Primary HCMV infection is characterized by an intense viral replication lasting for several months post-infection. We hypothesize that the high levels of viral replication observed during congenital and adult primary HCMV infection could interfere with some of the T cell functions.
Doctorat en Sciences biomédicales et pharmaceutiques
info:eu-repo/semantics/nonPublished

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Schneidereith, Tonya A. « The pharmacogenetics of fetal hemoglobin and f-cell variation ». Available to US Hopkins community, 2003. http://wwwlib.umi.com/dissertations/dlnow/308076.

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Ferreira, Leonardo. « Transcriptional Control of Maternal-Fetal Immune Tolerance ». Thesis, Harvard University, 2016. http://nrs.harvard.edu/urn-3:HUL.InstRepos:33493333.

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Human leukocyte antigens (HLA) are important determinants of self-nonself immune recognition. HLA-G, uniquely expressed in the placenta, is believed to be key to fetus-induced immune tolerance during pregnancy. The tissue-specific expression of HLA-G, however, remains poorly understood. Using a Massively Parallel Reporter Assay (MPRA), we discovered a 121 bp sequence 12 kb upstream of HLA-G with enhancer activity, Enhancer L. Strikingly, deletion of Enhancer L using a CRISPR/Cas9 dual guide approach resulted in complete ablation of HLA-G expression in a trophoblast cell line. This finding was confirmed in primary extravillous trophoblasts isolated from human placenta. RNA-seq analysis demonstrated that Enhancer L regulates HLA-G expression specifically. Moreover, DNase-seq and Chromatin Conformation Capture (3C) defined Enhancer L as a cell type-specific enhancer that loops into the HLA-G promoter. GATA2, GATA3, and CEBPB, factors essential for placentation, associate with Enhancer L and regulate HLA-G expression levels. These results establish long-range chromatin looping as a novel mechanism controlling trophoblast-specific HLA-G expression at the maternal-fetal interface.
Biology, Molecular and Cellular

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Wu, Pensée. « Muscular dystrophy cell therapy : an in utero approach using human fetal mesenchymal stem cells ». Thesis, Imperial College London, 2009. http://hdl.handle.net/10044/1/4726.

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Duchenne muscular dystrophy (DMD) is the most prevalent genetic neuromuscular disorder and affects 1 in 3,500 live male births. Lack of the protein dystrophin in muscle fibres causes permanent muscle damage, is lethal and despite various potential therapeutic strategies aimed at restoring dystrophin expression, has no cure. As DMD affects all skeletal muscles as well as the heart, a systemic treatment would be necessary and in utero stem cell transplantation is a promising way of achieving this. The identification of human fetal mesenchymal stem cells (hfMSC) in early gestation fetal blood offers the prospect of allogeneic or autologous cell therapy, while intrauterine administration would capitalise on ontological opportunities unique to the developing fetus. The aim of the study was to improve hfMSC engraftment and contribution to skeletal muscle fibres following intrauterine transplantation (IUT) in a mouse model of DMD. My project demonstrated that hfMSCs are easily isolated and expandable with the ability to undergo myogenesis in vitro. HfMSCs differentiated into mature myotubes following exposure to galectin-1 conditioned medium, while galectin-1 transduced hfMSCs showed significantly higher expression of myogenic markers compared to non-transduced hfMSCs. Co-culture experiments provided an in vitro model to explore the underlying mechanism for muscle differentiation of hfMSCs following IUT. HfMSCs were able to form chimeric myotubes by fusing with myoblasts isolated from E15 mouse embryos, evidence that they should be able to fuse with developing muscle fibres in vivo. Engraftment and differentiation into muscle fibres of hfMSCs injected intra-peritoneally into E15 mouse embryos in vivo was enhanced by using immunodeficient dystrophic host mice, postnatal muscle injury and additional neonatal hfMSC transplantation following IUT. In conclusion, my thesis supports the use of hfMSC as an attractive source for cell therapy and provides the background for further studies to optimise their engraftment and differentiation to underpin future clinical applications.

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Jones, Gemma Nicole. « The potential of fetal cell therapy for osteogenesis imperfecta using placenta derived stem cells ». Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/40291.

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Human mesenchymal stromal/stem cells (MSC) isolated from aborted first trimester fetal bone marrow (BM) hold promise for use in tissue engineering applications and cell-based therapies due to their advantageous characteristics compared to their adult BM-MSC counterparts; faster growth kinetics, active telomerase, smaller size and higher differentiation potency. However, their isolation is restricted ethically and technically and therefore there is a need to identify a cell source with high therapeutic potential that is easily accessible in the clinic without ethical restrictions. The placenta is a potential source of readily-obtainable chorionic stem cells (CSC) throughout pregnancy. The aim of my thesis was to study the evolution of the CSC phenotype (i.e. change of stem cell characteristics) during gestation and to assess their capacity for bone repair in a mouse model of osteogenesis imperfecta (oim). I hypothesised that early fetal placental chorionic stem cells (e-CSC) were physiologically superior to their term counterparts, late chorionic stem cells (l-CSC), with advantages for use in fetal stem cell therapy of osteogenesis imperfecta (OI). In the first chapter I showed that e-CSC and l-CSC shared a common phenotype, which was intermediate between adult BM-MSC and human embryonic stem cells, with characteristics of both. I also showed the phenotype of CSC evolves during gestation with e-CSC displaying characteristics of an earlier state of stemness compared to l-CSC, such as smaller size, faster kinetics, unique expression of OCT4A variant 1 and higher levels of Nanog, Sox2, c-Myc and Klf4 expression, as well as the capacity to differentiate into lineages of the three germ layers through embryoid body formation. In the second chapter I showed the more primitive in vitro characteristics of e-CSC translated to higher tissue repair in vivo compared to l-CSC; accelerating healing when applied to a skin wound and increasing bone quality and plasticity following neonatal transplantation into the oim model. I subsequently used the oim model to assess the therapeutic potential of e-CSC for use in fetal cell therapy for OI. I showed compared to non-transplanted mice, oim transplanted with e-CSC had a two third reduction in fracture incidence, more ductile bones and increased trabecular bone volume. Prevention of fractures was attributed to the differentiation of exogenous cells to osteoblasts that expressed mature osteoblast genes and synthesised human type 1 collagen (COL1A2). However, this beneficial effect may also have resulted from an indirect effect of the transplanted cells on the endogenous cells of the host mouse, since transplanted mice had upregulation of endogenous genes involved in endochondral ossification and osteoblast differentiation. Altogether, my thesis characterises early and late human fetal chorionic stem cells, providing insight into the ontogenesis of stemness phenotype during fetal development and shows the first trimester placenta is a practical source of stem cells that can be used to treat OI during bone development.

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Düber, Sandra. « B-cell development in fetal liver and adult bone marrow ». [S.l.] : [s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=973900164.

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Kosmin, Alan Simon. « Cell proliferation, apoptosis and migration within the human fetal retina ». Thesis, University of Liverpool, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366488.

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Porada, Christopher Daniel. « In vivo gene transfer into fetal animals / ». abstract and full text PDF (UNR users only), 1998. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:9833366.

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DOFFINI, ANNA. « A cell-based NIPD (Non-invasive prenatal diagnosis) procedure to select fetal cells from pregnant women maternal blood ». Doctoral thesis, Università degli Studi di Milano-Bicocca, 2022. http://hdl.handle.net/10281/365173.

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Attualmente i metodi di diagnosi prenatale esistenti, consentono di ottenere cellule fetali solamente mediante metodiche invasive che comportano un rischio sia per la madre che per il feto. La scoperta nel 1979 della presenza di cellule fetali circolanti nel sangue materno, ha aperto la strada per lo sviluppo di metodi non invasivi per l’identificazione di anomalie fetali. Tutti i metodi sviluppati fino ad oggi tuttavia sono risultati inefficienti nel garantire un adeguato numero di cellule fetali, essendo estremamente laboriosi, richiedendo molto tempo ed essendo operatori-dipendenti. Questo progetto ha lo scopo di sviluppare un metodo non invasivo per l’isolamento di singole cellule fetali dal sangue materno, per una analisi diretta dei cromosomi fetali. La prima parte è stata dedicata alla ricerca e test di diversi marcatori specifici per l’arricchimento e l’identificazione delle cellule fetali. Una volta messo a punto lo step di arricchimento, quest’ultimo è stato implementato e integrato in un worklow più ampio che prevedeva: prelievi di sangue da donne in gravidanza, arricchimento positivo magnetico, marcatura delle cellule fetali, isolamento come singole cellule e analisi genetica. Appena l’intero flusso è stato standardizzato abbiamo cominciato una valutazione clinica su donne in gravidanza. Al fine di determinare la percentuale di successo e il numero di cellule fetali per campione, un totale di 372 donne sono state reclutate e stratificate in base alla loro settimana gestazionale al momento del prelievo. Al meno una cellula fetale è stata isolata nel 90.7% dei casi prelevati tra la decima e undicesima settimana gestazionale, con un numero medio totale di 3.5 cellule fetali per paziente. Inoltre dati preliminari ottenuti da 131 donne che venivano sottoposte all’esame invasivo, hanno mostrato un alto livello di concordanza tra le cellule isolate singolarmente e analizzate con la nostra metodica e i risultati derivanti dall’esame diagnostico. Complessivamente, i risultati derivanti da questo studio, supportano la fattibilità clinica di un isolamento automatico e riproducibile delle cellule fetali circolanti ottenute in maniera non invasiva, da utilizzare per le analisi genetiche. Per questo motivo uno studio clinico di valutazione delle performance comincerà a breve su 1500 pazienti, reclutate in cinque diversi ospedali italiani. Obiettivi primari di questo studio saranno la valutazione delle performance in termini di sensibilità’ e specificità del metodo sviluppato, per il rilevamento delle aneuploidie fetali nelle gravidanze ad alto rischio. I risultati saranno comparati con i dati derivanti dalla diagnosi prenatale invasiva ottenuti dalle stesse donne che eseguiranno l’amniocentesi e la villocentesi. L’analisi comparativa determinerà i falsi postivi, falsi negativi, veri postivi e veri negativi del metodo sviluppato.
Current methods of prenatal diagnosis require fetal cells to be obtained through invasive procedures, risky for mother and fetus. The discovery of circulating fetal cells in 1979 and the possibility that these cells could be isolated from maternal blood during pregnancy was key to the development of alternative noninvasive approaches for identifying most fetal genetic abnormalities. All these methods result in a laborious, operator depending, time-consuming approach which until now it has not allowed to achieve a high and consistent purification of fetal cells. This project aims to develop a non-invasive method for the isolation of single fetal cells from maternal blood, for direct analysis of fetal chromosomes. The first part was dedicated to the research and testing of different specific markers for fetal cells enrichment and identification. Once optimized, the enrichment step was implemented to be automatic and integrated in a full workflow consisting of: pregnant women blood collection, positive magnetic enrichment, cell staining, single cell isolation and genetic analysis. As soon as the full workflow was standardized we started a clinical evaluation. To determine the success rate and number of trophoblast per sample, a total of 372 women were enrolled and stratified by gestational age at the time of blood collection. At least one fetal cell was isolated in 90.7% of the women sampled between 10-11 gestational weeks with an overall mean number of 3.5 recovered trophoblasts per patient. Furthermore, preliminary data from 131 women, showed a high concordance rate between isolated single trophoblastic cells and fetal karyotype for common trisomies and normal results deriving from gold standard invasive procedure. Overall, the results coming out from this study support the clinical feasibility of an automated and reproducible isolation of fetal cells for non-invasive prenatal genetic testing, well suited to the routine clinical practice. For this reason a clinical performance evaluation study will start soon, on 1500 patients, enrolled from five different Italian Hospital. Primary endpoints of the study will be the performance evaluation, in terms of sensitivity and specificity, of the developed workflow for fetal aneuploidies and segmental imbalances detection in a high-risk pregnancies population. Results will be compared with data resulting from invasive prenatal diagnosis for chromosomal abnormalities obtained on the same women presenting for hospital invasive procedure because classified from the physician as high risk pregnancy. The comparative analysis will determine the false positive, false negative, true positive, and true negative rates of the developed technology.

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Carney, Rosalind S. E. « Thalamocortical development and cell proliferation in fetal primate and rodent cortex ». Thesis, University of Oxford, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.418812.

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Attilakos, Georgios. « Study of Cell-Free Fetal DNA in Multiple and Complicated Pregnancies ». Thesis, University of Bristol, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.521087.

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Macko, Antoni Ryszard. « Elevated Fetal Plasma Norepinephrine Elicits Perinatal Adaptations in β-Cell Function ». Diss., The University of Arizona, 2013. http://hdl.handle.net/10150/311460.

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The objective of this dissertation research was to determine the specific actions of chronically elevated catecholamines on; 1.) fetal growth and ß-cell function during the third trimester in vivo in an ovine model of placental insufficiency-induced intrauterine growth restriction (PI-IUGR), and 2.) regulation of insulin secretion in vitro utilizing the mouse insulinoma cell line Min6.At 0.7-gestation, fetal weights were not different but PI fetuses had lower (P<0.05) basal blood oxygen content, plasma glucose, IGF-1, and insulin concentrations and greater norepinephrine concentrations (891±211 vs. 292±65 pg/ml; P<0.05) compared to controls. Glucose-stimulated insulin secretion (GSIS) was lower in PI than control fetuses (0.34±0.03 vs. 1.08±0.06 ng/ml; P<0.05). ADR-block increased GSIS in PI fetuses (1.19±0.11) but decreased GSIS in controls (0.86±0.02 ng/ml). Insulin content per islet was not different between PI and control fetuses. We concluded that elevated fetal plasma norepinephrine, in PI fetuses at 0.7 gestation, precedes growth restriction and suppresses insulin concentrations, and ADR-block revealed compensatory β-cells stimulus-secretion responsiveness. Therefore, to determine the effects of chronic hypercatecholamine exposure on fetal growth and β-cell function independent of hypoglycemia and hypoxemia, we performed surgical sham or adrenal demedullation (AD) at 0.65 gestation on control and IUGR fetuses (n= 5 Control-Sham, 5 Control-AD, 5 IUGR-Sham, 5 IUGR-AD fetuses). Studies commenced at 0.9 gestation under ambient conditions and steady-state reversal of arterial pO2 between IUGR and control fetuses. Plasma norepinephrine was 5-fold higher in IUGR-Sham vs. Control-Sham and reduced in IUGR-AD fetuses to concentrations not different from Control-Sham fetuses. Fetal mass was lower in IUGR vs. control fetuses but 92% greater in IUGR-AD compared to IUGR-Sham fetuses. Basal plasma glucose and arterial pO2 were lower in IUGR-Sham vs. Control-Sham, and IUGR-AD vs. Control-AD fetuses. Basal and glucose-stimulated insulin concentrations compared to Control-Sham were lower in IUGR-Sham and IUGR-AD and Control-AD fetuses. Oxygenation improved GSIS in IUGR-Sham and IUGR-AD fetuses. In conclusion, hypoglycemia, hypoxemia and norepinephrine interdependently and differentially regulate aspects of fetal growth and β-cell function in the IUGR fetus. In Min6 cells, we determined that GSIS responsiveness is enhanced and adrenergic receptor α2A is desensitized cells following chronic exposure to epinephrine.

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Mari, Chiara. « Generation and characterisation of progenitor cell lines from human fetal kidneys ». Thesis, University College London (University of London), 2018. http://discovery.ucl.ac.uk/10050589/.

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Kidney disease is a global public health burden. Chronic kidney disease, with an incidence increasing annually in the Western world, is a progressive kidney damage that can lead to end-stage renal failure (CKD5), in which kidney function is completely lost. CKD5 treatment options are dialysis, which is not a cure for kidney disease and kidney transplantation limited by the shortage of donor organs. Kidney disease new interventions have two aims: 1. preventing the progression to CKD5 2. creating a healthy organ in vitro with bioengineered scaffolds in order to permanently replace defective kidneys. The first aim involves the utilisation of drug- and cellular- based therapies to delay or to stop the progression to CKD5. However, this aim is made problematic by the paucity of available primary human renal cell lines to be used for new drugs testing and the incapability to accurately assess the efficacy of cellular-based therapies in appropriate animal models. The PhD Thesis illustrates the attempt in meeting this need. The thesis focuses on the generation and characterisation of human progenitor cell lines and further assessment of their potential to be used as cell-based therapy. I have generated human fetal cell lines from healthy kidneys, based on the expression of known markers of renal progenitor cells, CD24 and CD133. I have characterised their gene expression profile over multiple passages, assessing the expression of progenitor and lineage markers and evaluated their capacity to differentiate towards multiple lineages (osteoblasts, adipocytes and renal epithelia). Furthermore, the potential of these cells to be used as therapy has been assessed in mouse model of acute renal injury induced by folic acid after comparing the course of the folic acid-induced renal injury in immunocompetent and immunodeficient mice strains.

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Aguiar, Bruna Andrade. « Obtenção e caracterização de células derivadas do pâncreas fetal canino ». Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/10/10132/tde-07102016-120231/.

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A Diabetes mellitus em cães é cada vez mais frequente, decorrente de fatores genéticos e/ou ambientais, como um distúrbio endócrino que, de forma semelhante à que ocorre em humanos, falha no controle adequado de glicose no sangue, desencadeia a hiperglicemia, glicosúria e perda de peso. A terapia celular utilizando as células beta-pancreáticas tem sido alvo de estudos, devido à grande demanda de novos casos de Diabetes mellitus e à falta de órgãos para transplantes em humanos e animais. Acredita-se que a ciência possa responder e inovar em tratamentos, encontrando a possível cura para esta doença complexa. Portanto, o objetivo deste estudo foi obter e caracterizar células derivadas do pâncreas fetal canino de animais com idades compreendidas entre 50 e 60 dias de gestação. As células pancreáticas de fetos caninos apresentam morfologia fibroblastóide e crescimento em monocamada em cultivo, apresentam células pluripotentes e proliferativas, não são tumorigênicas e apresentam expressão de PDX1, um fator de transcrição que tem papel importante na ativação do gene promotor da insulina. O pâncreas possui inervação simpática, observado por fibras nervosas TH+. Histologicamente, o pâncreas fetal canino apresenta ácinos num estágio de organização avançado, com parênquima semelhante ao encontrado no cão adulto. As ilhotas pancreáticas são distribuídas no tecido de maneira irregular, organizando-se em pequenos aglomerados de células por entre os ácinos, especialmente próximas aos vasos sanguíneos. A coloração com Ditizona permitiu inferir a presença de insulina no tecido pancreático, o que foi comprovado mediante técnica de imunofluorescência, além da presença de células que expressam o hormônio somatostatina. Os resultados desta investigação indicam que o pâncreas fetal canino demonstra características favoráveis para ser uma fonte viável de células para estudos aplicados à terapia celular em cães. Outras investigações referentes à comprovação da produção de insulina in vitro por essas células se fazem necessárias
Diabetes mellitus in dogs is increasingly common, due to genetic and/or environmental factors such as an endocrine disorder, similarly to what occurs in humans, failure to adequately control blood glucose triggers hyperglycemia, glycosuria and weight loss. Cell therapy using the pancreatic beta cells has been the subject of studies, due to the great demand of new cases of diabetes mellitus and the lack of organs for transplants in humans and animals. It is believed that science can respond and innovate treatments, finding a possible cure for this disease complex. Therefore, the objective of this study was to obtain and characterize derived cells from canine fetal pancreas, of animals aged between 50 and 60 days of gestation. The pancreatic cells of canine fetuses exhibit fibroblastoid morphology and growth in monolayer culture, exhibit pluripotent and proliferative cells, are not tumorigenic and have PDX1 expression, a transcription factor that plays an important role in the activation of the insulin gene promoter. The pancreas has sympathetic innervation observed by TH+ nerve fibers. Histologically, the fetal pancreatic acini canine presents an advanced stage organization with similar parenchyma that found in adult dog. The pancreatic islets are distributed in the fabric unevenly, organizing themselves into small clusters of cells through the acini, especially close to the blood vessels. Staining with Dithizone allowed inferring the presence of insulin in the tissue, which was confirmed by immunofluorescence, in addition to cells that express somatostatin. The results of this investigation indicate that the canine fetal pancreas shows favorable characteristics to be a feasible source of cells for cell therapy applied to studies in dogs. Further investigation regarding the evidence of in vitro production of insulin by these cells are required

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Lindton, Bim. « Experimental studies of human fetal liver cells : in regard to in utero hematopoietic stem cell transplantation / ». Stockholm, 2002. http://diss.kib.ki.se/2002/91-7349-134-9.

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Lo, Yuk-Ming Dennis. « Molecular analysis of non-host cell-free DNA in human plasma and serum ». Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.365878.

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Myers, Kazimer Rene. « Correlation of membrane glycoconjugates and cell growth with the sensitivity of human glioma and fetal brain cells to natural killer cell cytolysis / ». The Ohio State University, 1989. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487670346874684.

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James-Allan, Laura B. « Decidual stromal cell regulation of the maternal-fetal interface in early pregnancy ». Thesis, St George's, University of London, 2016. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.719155.

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Decidualisation is the differentiation of endometrial stromal cells in to specialised secretory decidual stromal cells (DSC), which commences in the mid-secretory phase of the menstrual cycle and continues in pregnancy. During placentation, DSC regulate and control the invasion of extravillous trophoblast cells (EVT). In the decidua there is cross-talk between DSC and EVT and immune cells. The effect of DSC secreted factors on EVT and immune cell function in the first trimester of pregnancy was investigated. Pre-eclampsia is associated with inadequate trophoblast invasion and spiral artery remodelling. Uterine artery Doppler resistance index (RI) is used as a proxy measure of spiral artery remodelling. Pregnancies with a high RI are at increased risk of developing pregnancy complications, such as pre-eclampsia. The phenotype and function of DSC from normal and high RI pregnancies was compared. First trimester DSC were isolated from the decidua of terminations of pregnancy (n=93); these cells were able to re-decidualise in vitro. Conditioned media (CM) generated from normal and high RI DSC was used to study the effect of DSC-secreted factors on EVT and immune cell function. Results indicated that DSC CM from either normal or high RI pregnancies had no significant effects on EVT motility, proliferation or apoptosis. However, DSC CM from high RI pregnancies inhibited EVT chemotaxis (n=6, /?=0.046). Luminex array results demonstrated that DSC secrete an array of factors, however no difference was observed between normal and high RI DSC. DSC CM significantly stimulated decidual natural killer (dNK) cell IL-8 (n=T8,/?<0.0001) and IL-6 (n=18, /?=0.001) secretion but did not alter dNK or decidual macrophage receptor expression. In conclusion first trimester DSC secrete a wide range of factors that have roles in regulating trophoblast chemotaxis and dNK cell cytokine secretion. Although DSC secreted factors from pregnancies with a higher risk of pre-eclampsia were not altered, inhibited trophoblast chemotaxis may be contributing to abnormal placentation observed in conditions where remodelling is impaired, such as pre-eclampsia.

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Powell, Richard Morgan. « Novel T cell function and specificity at the human maternal-fetal interface ». Thesis, University of Birmingham, 2018. http://etheses.bham.ac.uk//id/eprint/8334/.

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The mechanisms by which immune tolerance is maintained during human pregnancy are unclear but include a range of modifications to the local and systemic maternal immune system. There is considerable T cell infiltration of the maternal decidua during pregnancy, however, the functional properties of this T cell response remains poorly defined. We investigated the specificity and regulation of CD4+ and CDS+ T cells in human third trimester decidua and show that the ratio of highly differentiated effector to naive CD4+ and CDS+ T cells is increased markedly in comparison to peripheral blood. Decidual T cells were also found to display a unique functional profile with simultaneous production of interferon-y (IFN -y) and interleukin 4 (IL-4 ). Decidual T cells proliferated in response to fetal tissue, a function that was regulated by T regulatory cells, and HY -specific T cells with high levels ofProgrammed Death Protein 1 (PD-1) were detectable in the decidua of women with male pregnancies. Transcriptional analysis of CD4+ and CDS+ decidual T cells revealed a unique gene profile characterized by elevated expression of proteins associated with the response to interferon signaling. These data have considerable importance for the investigation of fetal-specific alloreactive immune responses within disorders of pregnancy.

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Mitchell, Roderick T. « Germ cell development in the human and marmoset fetal testis and the origins of testicular germ cell tumours ». Thesis, University of Edinburgh, 2010. http://hdl.handle.net/1842/4818.

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Normal germ cell development in the human testis is crucial for subsequent fertility and reproductive health. Disruption of testis development in fetal life can result in deleterious health consequences such as testicular dysgenesis syndrome (TDS), which includes disorders, such as cryptorchidism, hypospadias, infertility and testicular germ cell tumours (TGCT). A rat model of TDS in which rats are exposed to phthalates in utero has been validated, but does result in the development of TGCT. In humans, TGCTs result from transformation of pre-neoplastic carcinoma in-situ (CIS) cells and these CIS cells are believed to arise from human fetal germ cells during their transition from gonocyte to spermatogonia, based on their morphology and protein expression profile. It has been proposed asynchronous differentiation of germ cells in the human fetal testis may predispose fetal germ cells to become CIS cells. Studying the development of these tumours in humans is difficult because of their fetal origins and prolonged duration from initiation of impaired development to invasive disease. For this reason the use of relevant animal models that can mimic normal and abnormal germ cell development may provide new insight into how TGCT develop. The Common Marmoset monkey, a New World primate exhibits many similarities to the human in terms of reproductive biology and could represent such a model. This thesis aimed to further characterise the origins of CIS cells in the human testis by investigating the protein expression profile of CIS cells in patients with TGCT and comparing them to established markers of human fetal germ cell types using immunohistochemistry and immunofluorescence. Quantification of the various subpopulations of CIS and proliferation within these populations was performed. The thesis also investigated the Common Marmoset monkey as a potential model of normal testis and germ cell development by comparing the differentiation and proliferation profile of germ cells with those of the human during fetal and early postnatal life. During the present studies methods were successfully developed that enabled us to use testicular xenografts to recapitulate normal development of immature testes from marmoset and human. This involved grafting pieces of testis tissue subcutaneously under the dorsal skin of immunodeficient mice and retrieving them several weeks later to investigate their development during the grafting period. Xenografts using tissue from fetal, neonatal and juvenile marmosets were performed in addition to testes from first and second trimester human fetuses. Finally the present studies aimed to use the marmoset and the xenografting approach as systems in which to examine the effects of gonadotrophin suppression and phthalate treatment on germ cell differentiation and proliferation, with particular attention to the potential for development of CIS and TGCT. Heterogeneous phenotypes of CIS cells were identified, mostly consistent with those seen in the normal human fetal testis, however some of these CIS cells did not exhibit the same phenotype as germ cells identified in normal fetal testes. In addition it was shown that some of the proteins considered to be ‘classical’ markers of CIS cells, such as the pluripotent transcription factor OCT4, were not expressed in a proportion of the CIS cells. The proliferation index of CIS cells is also significantly higher in those subpopulations with the most ‘undifferentiated’ phenotype (i.e. OCT4+/VASA-). The present studies have generated novel data showing that the marmoset is a good model of fetal and neonatal germ cell development, with similarities to the human in terms of an asynchronous and prolonged period of differentiation and proliferation of germ cells from gonocyte to spermatogonia. This feature is also common to the human, but not a characteristic of the rodent. Fetal, neonatal and pre-pubertal germ cell development can be re-capitulated by xenografting tissue from marmoset and human testes into nude mouse hosts. Human fetal testis grafts produced testosterone and were responsive to hCG stimulation. First trimester human testis xenografts that have not developed fully formed seminiferous cords prior to grafting can complete the process of cord formation whilst grafted in host mice. In addition, germ cells in fetal human and marmoset xenografts can differentiate and proliferate in a similar manner to that seen in the intact non-grafted testis. In the intact neonatal marmoset, suppression of gonadotrophins resulted in a 30% decrease in proliferation, however differentiation of gonocytes is not affected. In-utero treatment of neonatal marmosets with mono-n-butyl phthalate was associated with unusual ‘gonocyte’ clusters, however, di-n-butyl phthalate treatment of mice carrying fetal marmoset xenografts resulted in no visible effects on germ cell differentiation or proliferation and did not result in the development of CIS or TGCT. In conclusion, this thesis has shown that there are many subpopulations of CIS cells of which many have not been previously described. These subpopulations have different characteristics, such as variable proliferation rates and this may indicate the potential for progression or invasiveness. These subpopulations have similar protein expression phenotypes to normal human fetal germ cells although the present studies have identified some CIS cells with phenotypes that are not found in the normal human testis. This thesis has demonstrated that the marmoset is a comparable model to the human in terms of asynchronous fetal germ cell development, which may predispose this species to the development of CIS/TGCT. In addition to the use of intact marmosets, these studies have also demonstrated for the first time that testis xenografting provides a comparable system for testis cord formation, germ cell differentiation and proliferation in fetal/postnatal marmosets and fetal human testis. In addition the marmoset and xenografting models have indicated that phthalates may have minor effects on testis development in the human and marmoset but do not result in CIS or TGCT. These model systems are suitable for further investigation of normal and disrupted testis development.

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Rounioja, S. (Samuli). « Experimental mouse model for fetal inflammatory response ». Doctoral thesis, University of Oulu, 2005. http://urn.fi/urn:isbn:951427783X.

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Abstract Intrauterine infections apparently cause about 85% of preterm deliveries at less than 28 weeks of gestation. Infection and inflammation play an important role in morbidity and mortality during perinatal period. The inflammatory mechanisms and pathophysiological consequences of intrauterine infection are poorly understood. According to current evidence from animal studies, the phenotypes of fetal inflammatory response are variable, ranging from spontaneous preterm birth to fetal death. The fetus is rather well protected against infectious agents by both structural and functional barriers. Toll-like receptors (TLR) are a part of innate immune system. Binding of bacterial or viral component to TLR induces inflammatory response in the host. The present study addressed the hypothesis that the effects of bacterial lipopolysaccharide (LPS) on the fetus, depends on the route by which it reaches the fetus. In this experimental study we hypothesized that an acute inflammation within the amniotic cavity may cause an innate immune response in the fetus consequently leading to cardiovascular distress. Secondly the role of the placenta in protecting the fetus from acute infectious challenges was evaluated. Additionally, the role of gestational age in the fetal immune response was studied. In the present study, LPS from Gram-negative bacteria caused an acute intrauterine inflammation in mice as indicated by the elevated levels of inflammatory mediators (e.g. cytokines) in amniotic fluid. The fetal heart revealed mRNA and protein expression of TLR4, which recognizes LPS. Moreover, the data showed a cytokine response in the fetal heart and severe cardiac dysfunction. In contrast, intraperitoneal LPS administered to the mother did not cause an acute cytokine response in the fetus. After intraperitoneal LPS the placenta showed severe blood congestion and a cytokine response. The data suggest that TLRs play roles in regulating the acute inflammatory responses in the placenta. Despite the absence of a fetal immune response, the placental lesions caused a fetal cardiovascular compromise. In addition, the present data indicate that the fetal expression of TLR4 is tissue specific and developmentally regulated. Present study provides new insights into the acute inflammatory mechanisms in maternal and fetal compartments and the pathophysiological changes in fetal cardiovascular hemodynamics
Tiivistelmä Hyvin ennenaikaisen, alle 28. raskausviikolla tapahtuneen synnytyksen taustalta löytyy usein kohdunsisäinen infektio (IUI). Kohdunsisäisen infektion aiheuttama synnytys on suurimpia sikiön vammautumiseen tai kuolemaan johtavia syitä. Tulehdukselliset mekanismit, jotka johtavat synnytykseen tai sikiön vammautumiseen ovat huonosti tunnettuja. Tollin kaltaiset reseptorit (TLR) ovat osa synnynnäisen immuniteetin puolustusjärjestelmää. Niiden tarkoitus on tunnistaa nopeasti elimistölle vieraat, usein bakteeri- tai virusperäiset rakenteet ja käynnistää tulehdusvaste tuottamalla tulehdusvälittäjäaineita. Nämä välittäjäaineet säätelevät tulehdusprosessia, toisaalta niiden liiallinen tuotto voi aikuisilla johtaa elinvaurioihin kuten sydämen toimintahäiriöön. On esitetty että tulehdusvälittäjäaineet käynnistäisivät myös ennenaikaisen synnytyksen IUI:ssa. TLR-reseptorien merkityksestä sikiön tulehdusvasteessa tai synnytyksen käynnistymisessä on vain vähän tietoa. Väitöskirjatyössä tutkittiin kokeellisen hiirimallin avulla bakteeriperäisen lipopolysakkaridin (LPS) kykyä aiheuttaa sikiön tulehdusvaste, sekä muutoksia sikiön sydämen ja verenkierron toiminnassa, riippuen LPS:n reitistä sikiöön. Toisaalta kokeellisella mallilla tutkittiin istukan kykyä suojata sikiötä voimakkaalta tulehdusreaktiolta. Tarkoituksena oli tutkia myös sikiön kehitysasteen vaikutusta LPS:n aiheuttamaan tulehdusvasteeseen. Tutkimuksessa havaittiin LPS:n aiheuttavan kohdunsisäisen tulehduksen kun sitä annettiin suoraan lapsiveteen. Sikiön sydämessä todettiin TLR4 lähetti-RNA:n ja proteiinin ilmentyminen sekä nopea sytokiinien tuotannon lisääntyminen kuvastaen äkillistä tulehdusprosessia. Samanaikaisesti ultraäänitutkimuksessa todettiin sikiön sydämen vaikea toimintahäiriö. Toisaalta, jos LPS annettiin kantavalle emolle vatsaonteloon, tulehdusvälittäjäaineiden tuotannon lisääntymistä sikiössä ei havaittu. Sen sijaan istukassa todettiin akuutti verentungos ja tulehdusvaste. Edellä kuvattu istukan toimintahäiriö johti myös sikiön sydämen ja verenkierron toiminnan vaikeutumiseen huolimatta siitä, ettei sikiön sydämessä havaittu tulehduksellista vastetta. Lisäksi sikiöstä ja istukasta saadut tulokset viittaavat siihen, että TLR-reseptorit ovat mukana LPS:n tunnistamisessa ja äkillisen tulehdusvasteen käynnistymisessä. Tutkimus antaa uutta tietoa raskauden aikaisista tulehduksellisista mekanismeista sekä sikiön sydämen toiminnan äkillisistä muutoksista voimakkaan tulehduksen aikana

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Ene, Adriana. « Meiotic prophase progression and germ cell elimination in fetal and neonatal mouse ovaries ». Thesis, McGill University, 2010. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=92367.

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In most mammalian species, all oogonia cease mitotic proliferation and enter meiosis in fetal ovaries. Furthermore, more than half of the maximum number of germ cells is eliminated from ovaries by neonatal life, thus limiting the oocyte reserve for reproduction. The cause or mechanism of this female germ cell loss remains largely unknown. A major loss occurs in the oocytes which reach the pachytene stage of meiotic prophase, suggesting that oocytes with meiotic or recombination errors may be eliminated by a checkpoint mechanism. It remains to be determined whether oocytes are eliminated by apoptosis and if so in which pathway. The purpose of my study is to investigate a mechanism of oocyte loss in the mouse ovary during meiotic prophase. We used an Msh5 null mutant mouse strain, in which all oocytes are eliminated by neonatal life. Msh5 encodes a protein required for meiotic chromosome synapsis.
Msh5 heterozygous mutant mice were crossed and ovaries were isolated from female progeny at 14.5 22.5 days postcoitum (dpc). We studied the loss of germ cells in Msh5 -/- (MT) females comparing to the Msh5 +/+ (WT) and Msh5 (+/-) (HT) females by immunolabeling of ovarian sections for GCNA1 or MVH (both germ cell markers) or by counting GCNA1 positive germ cells in cell suspension preparations. Our results showed a continuous loss of GCNA1 positive cells in both MT and WT although the loss in MT was constantly larger than in the WT. A significant difference between WT and MT was found at 19.5 dpc.
Meiotic progression was studied by GCNA1 and SC (synaptonemal complex) or SC and ɣH2AX double immunolabeling of chromosome spread preparations. We found that meiosis in MT was blocked at zygotene-pachytene transition. No normal pachytene was observed in MT.
The role of apoptosis in elimination of oocytes during meiotic prophase was investigated by analyzing the cleavage of various caspases (caspase 2, 3, 6, 7, 9) as well as PARP1 by western blot using the lysate of whole ovaries. The activation of initiator caspase 9 increased from 17.5 to 18.5 dpc and decreased by 19.5 dpc. Caspase 2L activation also increased in a similar pattern but at much lower levels. The activation of effector caspase 3 or 6 remained at low levels. The activation of caspase 7 also was low but increased slightly at 19.5 dpc. The cleavage of PARP1 was high at all investigated stages. There were not major differences in the average level of activation between WT and MT. By immunolabeling of ovarian sections we observed that cleaved caspases and PARP1 were localized in oocytes but also in cells negative for GCNA1.
These results suggest that a mitochondrial pathway of apoptosis may play a role in the elimination of oocytes during meiotic prophase, involving activation of caspase 9 and cleavage of PARP1. However further studies are necessary for identification of an effector caspase.
Dans la plupart des espèces de mammifères, tous les oocytes cessent la prolifération mitotique et initialisent la méiose dans les ovaires ftales. En outre, plus de la moitié du nombre maximal de cellules germinales est éliminée dans les ovaires pendant la vie néonatale, limitant ainsi la réserve d'oocytes pour la reproduction. La cause ou le mécanisme de cette perte de cellules germinales femelles reste largement inconnu. Une perte majeure se produit dans les oocytes qui atteignent le stade pachytène de la prophase méiotique, suggérant que les oocytes avec des erreurs dans la méiose ou des erreurs de recombinaison peuvent être éliminés par un mécanisme de contrôle. Il reste à déterminer si les oocytes sont éliminés par apoptose, et si oui, par quel méchanisme. Le but de mon projet est d'étudier un mécanisme de perte d'oocytes dans les ovaires de souris durant la prophase méiotique. Nous avons utilisé une souche de souris mutantes pour la gene Msh5, dans lequelles tous les oocytes sont éliminés durant la vie néonatale. Msh5 code pour une protéine nécessaire à la synapse de chromosomes méiotiques.
Des souris hétérozygote Msh5 ont été croisées et les ovaires ont été isolées de la progéniture féminine de 14,5 à 22,5 dpc. Nous avons étudié la perte de cellules germinales dans les ovaires des femelles Msh5 -/- (MT) en les comparant à ceux des femelles Msh5 +/+ (WT) et Msh5 +/- (HT) par immunodétection en utilisant des anticorps anti-GCNA1 et anti-MVH (marqueurs des cellules germinales) ou par le comptage des cellules positives au GCNA1 dans des suspensions cellulaires. Nos résultats montrent une perte continue de cellules positives au GCNA1 chez les souris MT et WT, bien que la perte chez les MT a été constamment supérieure à celle des WT (différence significative à 19.5 dpc).
La progression de la méiose a été étudiée par immunodétection double pour GCNA1 et SC (complexe synaptonémal) ou pour SC et γH2AX sur des préparations de chromosomes. Nous avons constaté que la méiose chez les souris MT est bloquée dans le stage de transition zygotène-pachytène. Nous n'avons pas observé de pachytène normal chez les souris MT.
Le rôle de l'apoptose dans l'élimination d'oocytes au cours de la prophase méiotique a été étudié par analyse du clivage de diverses caspases (caspases 2, 3, 6, 7, 9) ainsi que celui de la PARP1 par immunobuvardage des protéines d'ovaires entières lysées. L'activation de la caspase 9 initiatrice a augmenté entre 17.5dpc et 18.5 dpc et a ensuite baissé à 19.5 dpc. Celle de la caspase 2L a augmenté d'une manière semblable, mais à des niveaux beaucoup plus bas. L'activation des caspases effectrice 3 et 6 est demeurée à des niveaux faibles mais celle de la caspase 7 bien que faible a augmenté légèrement à 19.5 dpc. Le clivage de PARP1 était élevé dans tous les stages. Dans tous ces cas, il n'y a pas eu de grandes différences dans le niveau moyen d'activation entre WT et MT. Par immunodétection de sections d'ovaires, nous avons observé que les caspases et PARP1 clivées étaient localisées dans des oocytes, mais aussi dans les cellules sans marquage pour GCNA1.
Ces résultats indiquent que la voie mitochondriale de l'apoptose peut jouer un rôle dans l'élimination d'oocytes au cours de la prophase méiotique, puisque les clivages de la caspase 9 et de PARP1 y sont associés. Cependant des études supplémentaires sont nécessaires pour l'identification de caspases effectrices.

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Ofori-Acquah, Solomon Fiifi. « Molecular basis for CIS regulation of fetal haemoglobin expression in sickle cell disease ». Thesis, King's College London (University of London), 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.324882.

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Zehri, Aqib Hyder. « Differential Effects of Pulsatile vs. Chronic Hyperglycemia on Fetal Pancreatic Beta Cell Population ». Thesis, The University of Arizona, 2011. http://hdl.handle.net/10150/145129.

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Middlebrook, Aaron J. « Nicotine and TNF alpha, modulators of T cell signaling-effects on T cell development in fetal thymus organ culture ». Diss., The University of Arizona, 2004. http://hdl.handle.net/10150/280628.

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T cell development is regulated by signals generated in the interactions between developing thymocytes and the thymic stroma. Using fetal thymus organ culture (FTOC) as a model of T cell development, we investigated the ability of two potent signal modulators to influence this process. These studies show that both nicotine and tumor necrosis factor-alpha have the ability to influence T cell receptor (TCR) signaling and the maturational capacity of treated cultures. FTOC treated with low concentrations of nicotine produced more immature T cells and fewer mature T cells. These expanded populations of cells also expressed CD69, CD95 (FAS) and elevated levels of recombinase activating genes (RAG). This phenotype reflects the fact that these cells have received a positive selection signal, are for apoptosis and are likely attempting secondary TCR rearrangements. Nicotine effects were partially blocked by the nicotinic antagonist, d-tubocurarine. Furthermore, d-tubocurarine alone blocked the development of T cells entirely, suggesting the presence of an endogenous ligand that may engage nicotinic acetylcholine receptors and regulate normal thymopoeisis. These observations underscore the linkage between the nervous and the immune systems, not only in terms of shared resources, but also in terms of direct interactions between these two systems. In another study we used FTOC and an associated in vitro Type 1 diabetes mellitus model to reconcile the role of TNF-alpha in thymopoiesis with its role in diabetes. Our data indicate that thymocytes from NOD FTOC express lower levels of TNF receptors and produce more TNF-alpha compared to non-diabetic C57BL/6 (B6) FTOC. Neutralization of endogenous TNF-alpha in NOD FTOC with a soluble TNF receptor (sTNF R1) rescued insulin production in our in vitro diabetes model. NOD FTOC treated with TNF-alpha produced greater numbers of mature T cells and a higher percentage of cells expressing CD95L (Fas ligand). Treatment with sTNF R1 had the opposite effect. TNF-alpha's known ability to attenuate TCR signaling coupled with these observations suggest that its overproduction in these animals may be driving T cells to maturity, altering the process of negative selection and ultimately enhancing the survival of potentially diabetogenic T cells resulting in disease susceptibility in these animals.

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Wang, Xin. « Endothelial cell activation and injury in umbilical placental vascular disease ». Thesis, The University of Sydney, 2003. https://hdl.handle.net/2123/27854.

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Flansburg, Carroll Nicole. « Is Sickle Cell Trait as Benign as is Usually Assumed ? » Scholar Commons, 2014. https://scholarcommons.usf.edu/etd/5017.

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Abstract Introduction Sickle cell trait carriers may experience sickling events, which can cause severe health problems. Some sickle cell haplotypes contain genetic modifiers that are associated with increased levels of fetal hemoglobin, which is resistant to sickling. The aim of this study is to determine if sickle cell trait individuals who do not carry these modifiers are more likely to experience sickling episodes than those who do carry the modifiers. Methods: Participants were eligible for inclusion in this study if they were male, 18 years of age or older, a sickle cell trait carrier, and had previously played any level of organized football. Participants were recruited via Facebook, www.clinicaltrials.gov, e-mail, phone calls, and word of mouth. They were asked to complete a survey and return a buccal swab for genetic analysis to look for alleles associated with fetal hemoglobin persistence. To date, no genetic analyses have been run. Data from the surveys was analyzed using Fisher's Exact Test with the SAS 9.2 software. Results: Twenty participants were included in this phase of the study and all returned both the survey and buccal swab. Five of the 20 participants had been diagnosed with exertional sickling, 2 with heat illness, and 12 had experienced dehydration. Conclusion: Data in this study is purely observational, as no genetic analyses have been performed at this point. Early results indicate that the probability a player feels their muscle pain lasts longer than their peers' is greater among those who feel it takes their muscles longer to recover than their peers'.

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Gill, Jagjit Singh. « Immunocytochemical characterization of components of the hemopoietic microenvironment in the mouse fetal liver ». Thesis, McGill University, 1989. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=59386.

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The fetal liver plays an important role in hemopoiesis during mammalian development. Morphological and immunocytochemical studies were carried out to identify and characterize cellular components that may be responsible for producing the liver hemopoietic environment. Cytospot preparations, from fetal livers of 11-18 days gestation, reacted with specific antibodies enabled us to characterize and quantitate the different cell populations.
Light microscope observations also showed areas of close cell associations involving two classes of central cells and peripheral erythroid cells. Such associations were distinguished based on their immunocytochemical characteristics (AFP vs. Mac-1 central cells) and quantitative appearance throughout cytospots.
The presence of these significant cell associations was also observed in ultrastructural studies that produced further characteristics of these central cells. Characteristic lipid inclusions, glycogenic particles and positive AFP reactions were localized to central hepatocytes. Macrophages in cell associations contained numerous phagocytic particles and distinct peroxidase activity within the nuclear envelope and endoplasmic reticulum. Extra-cellular matrix components of electron dense nature were noted to emanate from delicate cytoplasmic processes that appeared to keep these associations intact. Fibronectin positive reactions were also specifically localized to central hepatocytes in cell associations. Further morphological and immunocytochemical features of these cell associations in the liver hemopoietic microenvironment are discussed.

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Dimovski, Aleksandar Jovo. « Factors affecting the fetal hemoglobin levels in patients with sickle cell anemia and thalassemia ». [Maastricht : Maastricht : Rijksuniversiteit Limburg] ; University Library, Maastricht University [Host], 1993. http://arno.unimaas.nl/show.cgi?fid=6583.

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Puszyk, William Matthew. « Epigenetics of cell-free plasma DNA for non-invasive prenatal diagnosis of fetal aneuploidies ». Thesis, University of Warwick, 2008. http://wrap.warwick.ac.uk/1059/.

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Since the discovery of cell-free fetal DNA in the circulation of pregnant women fetal-specific DNA biomarkers for non-invasive prenatal diagnosis of fetal aneuploidy have been sought. A model system assessing the DNA methylation of placental DNA and adult peripheral leukocyte DNA has been developed previously to represent fetal and maternal plasma DNA. To use DNA methylation to detect specific DNA molecules it is desirable that cellfree plasma DNA maintains the methylation profile of its tissue source. Using the imprinted gene GNAS1, a test has been developed to assess, for the first time the relative abundance of methylated and unmethylated DNA circulating in plasma. Methylated and unmethylated DNA sequences were found in equal abundance. If this finding is applicable to all plasma DNA sequences, we conclude that the steadystate concentration of DNA in methylated and unmethylated form is a reliable indicator of its input into the circulation. We have also investigated whether the abundances of different single copy gene sequences in cell-free plasma DNA are equal. Using real-time PCR, the relative abundances of six unique genomic DNA sequences in plasma were assessed. We find that plasma DNA from different sequences is not present in equal abundance in normal healthy individuals. The relative abundance of sequences tested differed by as much as 12.3 fold. We present a panel of novel candidate epigenetic biomarkers which have been identified using the model system. Of 366 DNA regions tested 3% were found to be differential. Further characterisation of these candidate epigenetic biomarkers has revealed limitations of the model system. In view of these results, future epigenetic biomarker development should be achieved by a direct assessment of first trimester plasma DNA.

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Cannon, Matthew. « Large-scale Investigation of Fetal Hemoglobin Modulators and Inflammation Biomarkers in Sickle Cell Disease ». The Ohio State University, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=osu16188574420699.

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Ramond, Cyrille. « Early T cell development in Mus Musculus : characterization of the fetal thymic settling progenitors ». Paris 6, 2012. http://www.theses.fr/2012PA066452.

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Le thymus ne possède pas la capacité d’auto-renouvellement, il est dépendant de la migration de progéniteurs hématopoïétiques provenant du foie fœtal et de la moelle osseuse. La nature du Progéniteur Migrant au Thymus (PMT) reste inconnue et la caractérisation des Progéniteurs Thymiques Précoces (PTP) est sujette à controverse. Les PTP de jour Embryonnaire 12 (E12) sont restreints au potentiel T tandis que ceux du nouveau né gardent des potentiels de différenciation dans les voies B et myéloïde. Au cours de cette étude, nous avons analysé le compartiment des DN1 fœtal de jour E12 jusqu’au stade du nouveau né. Nous avons ainsi démontré qu’une sous population appartenant au DN1a exprime les marqueurs CD135 et CD127. Elle est restreinte au potentiel T et a pour origine directe le PMT. Le PMT est restreint au potentiel T avant même l’entrée dans le thymus et nous proposons un modèle de différenciation des sous populations des DN1 fœtaux. De plus, nous avons démontré que les PMT ont pour origine une sous population du progéniteur commun aux cellules lymphoïdes qui exprime un faible niveau de CD24. Nous avons des indications indiquant que les cellules endothéliales du foie fœtal seraient à l’origine de la perte du potentiel B des PMT en circulation. Nous montrons, également que la migration des PMT au thymus s’effectue en deux phases distinctes: la première se déroule de jours E12 à E15 phase durant laquelle le PMT est restreint au potentiel T; la seconde de jour E15 au stade nouveau né, phase durant laquelle le PMT garde les potentiels de différenciation dans les voies B et myéloïde. Nos résultats permettent d’identifier les étapes clefs du développement T de jour 12 au stade nouveau né
The thymus lack self-renewal capacity and is dependent on an input of hematopoietic progenitors from the fetal liver and the bone marrow. The nature of the thymic settling progenitors (or TSPs) remains elusive and the characterization of the earliest thymic progenitors (or ETPs) is controversial. The ETPs from Embryonic day 12 (E12) are T restricted while newborn and adult ETPs display B cell and myeloid potential. In this study we have analyzed the first fetal thymic compartment (DN1) from E12 to newborn. We have demonstrated that a subset of DN1a expressing CD135 and CD127 is T restricted and derived from TSPs that are T bias prior to the entry into the thymus. Furthermore we propose a developmental model of fetal DN1 subsets. Moreover, we have shown that the TSPs are coming from a subset of fetal liver common lymphoid progenitor that expresses low level of CD24. We provide evidences that fetal liver endothelial cells may be responsible for the lost of B cell potential in the migrating TSPs. Additionally we show that the seeding of the thymus occurs in two different phases. The first one from E12 to E15 where the TSPs are T bias and the second from E15 to newborn where the TSPs retain B and myeloid potentials. Our results provide the missing link between E12 and newborn

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Barkley, Nicole Marie Garverick Henry Allen. « Characterization of apoptosis in the developing bovine fetal ovary association with germ cell loss / ». Diss., Columbia, Mo. : University of Missouri-Columbia, 2008. http://hdl.handle.net/10355/6105.

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The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract, appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on October 9, 2009) Thesis advisor: Dr. H. Allen Garverick. Vita. Includes bibliographical references.

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Stephen, Jillian. « Characterisation of effector and regulatory T-cell responses to blood group antigens ». Thesis, Available from the University of Aberdeen Library and Historic Collections Digital Resources, 2008. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?application=DIGITOOL-3&owner=resourcediscovery&custom_att_2=simple_viewer&pid=24752.

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Herrera-Gonzalez, Norma Estela. « Analysis of specfic immunoglobulin-secreting cells in the mid gestation mouse embryo : their potential role in fetal survival ». Thesis, Open University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292371.

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Okumura, Leah M. « Germ cell nuclear factor is not required for the down-regulation of pluripotency markers in fetal ovarian germ cells ». Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/77781.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Biology, 2012.
Cataloged from PDF version of thesis.
Includes bibliographical references.
In mouse, germ cells retain expression of the pluripotency markers Oct4 and Nanog longer than any other cells in the body. While somatic cells repress these markers during gastrulation, female germ cells continue to express them until around the time of meiotic initiation. It is not yet clear why pluripotency markers are downregulated with this particular timing, nor is it understood what factors are involved in their repression. I have examined in fetal ovarian germ cells the expression and function of Gcnf (germ cell nuclear factor), an orphan nuclear receptor known to regulate both Oct4 and Nanog in gastrulating embryos. I have found that Gcnf is expressed in a female germ-cell-specific manner at the time when Oct4 and Nanog are down-regulated there. Gcnf mutants in which the ligand binding domain is disrupted display defects after gastrulation comparable to those observed in Gcnf-null mutants and those lacking the DNA binding domain. In contrast, the germ cells Gcnfligand binding domain mutants show no failure in repression of pluripotency markers, and other aspects of female germ cell development appear normal as well. Thus, it appears that the ligand binding domain of GCNF is not required for fetal ovarian germ cell development.
by Leah M. Okumura.
Ph.D.

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Chen, Xiaochuan, Amy C. Kelly, Dustin T. Yates, Antoni R. Macko, Ronald M. Lynch et Sean W. Limesand. « Islet adaptations in fetal sheep persist following chronic exposure to high norepinephrine ». BIOSCIENTIFICA LTD, 2017. http://hdl.handle.net/10150/623222.

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Complications in pregnancy elevate fetal norepinephrine (NE) concentrations. Previous studies in NE-infused sheep fetuses revealed that sustained exposure to high NE resulted in lower expression of α2-adrenergic receptors in islets and increased insulin secretion responsiveness after acutely terminating the NE infusion. In this study, we determined if the compensatory increase in insulin secretion after chronic elevation of NE is independent of hyperglycemia in sheep fetuses and whether it is persistent in conjunction with islet desensitization to NE. After an initial assessment of glucose-stimulated insulin secretion (GSIS) at 129 ± 1 days of gestation, fetuses were continuously infused for seven days with NE and maintained at euglycemia with a maternal insulin infusion. Fetal GSIS studies were performed again on days 8 and 12. Adrenergic sensitivity was determined in pancreatic islets collected at day 12. NE infusion increased (P < 0.01) fetal plasma NE concentrations and lowered (P < 0.01) basal insulin concentrations compared to vehicle-infused controls. GSIS was 1.8-fold greater (P < 0.05) in NE-infused fetuses compared to controls at both one and five days after discontinuing the infusion. Glucose-potentiated arginine-induced insulin secretion was also enhanced (P < 0.01) in NE-infused fetuses. Maximum GSIS in islets isolated from NE-infused fetuses was 1.6-fold greater (P < 0.05) than controls, but islet insulin content and intracellular calcium signaling were not different between treatments. The half-maximal inhibitory concentration for NE was 2.6-fold greater (P < 0.05) in NE-infused islets compared to controls. These findings show that chronic NE exposure and not hyperglycemia produce persistent adaptations in pancreatic islets that augment β-cell responsiveness in part through decreased adrenergic sensitivity.

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Zabihi, Sheller. « Fetal Outcome in Experimental Diabetic Pregnancy ». Doctoral thesis, Uppsala University, Department of Medical Cell Biology, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-8739.

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Women with pregestational diabetes have a 2-5 fold increased risk of giving birth to malformed babies compared with non-diabetic women. Diabetes-induced oxidative stress in maternal and embryonic tissues has been implicated in the teratogenic process. The malformations are likely to be induced before the seventh week of pregnancy, when the yolk sac is partly responsible for the transfer of metabolites to the embryo, and the uterine blood flow to the implantation site determines the net amount of nutrients available to the conceptus. We aimed to evaluate the effect on embryogenesis caused by a diabetes-induced disturbance in yolk sac morphology, uterine blood flow or altered maternal antioxidative status in conjunction with a varied severity of the maternal diabetic state.

We investigated to which extent maternal diabetes with or without folic acid (FA) supplementation affects mRNA levels and protein distribution of ROS scavenging enzymes (SOD, CAT, GPX), vascular endothelial growth factor-A (Vegf-A), folate binding protein-1 (Folbp-1), and apoptosis associated proteins (Bax, Bcl-2, Caspase-3) in the yolk sacs of rat embryos on gestational days 10 and 11. We found that maternal diabetes impairs, and that FA supplementation restores, yolk sac vessel morphology, and that maternal diabetes is associated with increased apoptotic rate in embryos and yolk sacs, as well as impaired SOD gene expression. We assessed uterine blood flow with a laser-Doppler-flow-meter and found increased blood flow to implantation sites of diabetic rats compared with controls. Furthermore, resorbed and malformed offspring showed increased and decreased blood flow to their implantation sites, respectively. In mice with genetically altered CuZnSOD levels, maternal diabetes increased embryonic dysmorphogenesis irrespective of CuZnSOD expression. We thus found the maternal diabetic state to be a major determinant of diabetic embryopathy and that the CuZnSOD status exerts a partial protection for the embryo in diabetic pregnancy.

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El, Hoss Sara. « Novel insights into the role of fetal hemoglobin in spleen function, red cell survival and ineffective erythropoiesis in sickle cell disease ». Thesis, Université de Paris (2019-....), 2019. https://theses.md.univ-paris-diderot.fr/ELHOSS_Sara_va2_20190924.pdf.

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La drépanocytose est une maladie génétique héréditaire récessive causée par la substitution d'un acide aminé dans la chaîne β-globine aboutissant à la production d'hémoglobine anormale (HbS). Dans des conditions hypoxiques, l’HbS polymérise entraînant une falciformation et une perte de déformabilité des globules rouges (GR). Au cours de la drépanocytose, le dysfonctionnement splénique entraîne des complications potentiellement mortelles, en particulier chez les jeunes enfants. Généralement, une asplénie fonctionnelle précède la survenue d’une asplénie anatomique avec cependant une grande variabilité inter-individuelle du fait de facteurs modulateurs génétiques et environnementaux. L’hémoglobine fœtale (HbF) est le principal modulateur de la gravité de la maladie, car la présence d’HbF inhibe la polymérisation d’HbS, retardant et prévenant ainsi les complications graves, améliorant la qualité de vie des patients et augmentant leur survie. Il existe une hétérogénéité assez bien caractérisée de la concentration et de la distribution cellulaire d'HbF dans les GR circulants, mais le rôle de l'HbF au cours de l'érythropoïèse est mal documenté.Dans le but de mieux comprendre le rôle de l’HbF dans la perte de fonctionnalité splénique, la survie des GR et l'érythropoïèse inefficace, nous avons étudié 1) l'histoire naturelle du dysfonctionnement splénique chez les enfants drépanocytaires, 2) l'expression cellulaire et la distribution de l'HbF comparativement chez les enfants, chez les patients naïfs et ceux traités par hydroxycarbamide (HC) et 3) le rôle de l'HbF au cours de l'érythropoïèse terminale.Nous avons d’abord développé une méthode de cytométrie en flux à haut débit pour mesurer la fonction de filtration splénique et avons montré que la perte de fonction splénique est présente très tôt dans la vie, dès 3 à 6 mois chez les enfants drépanocytaires, puis diminue avec l'âge. Nous avons également mis en évidence que les cellules irréversiblement falciformées (ISC) jouaient un rôle dans la survenue de la séquestration splénique aiguë, laquelle entraîne à son tour une perte supplémentaire de fonction. Dans la deuxième partie de ce travail, nous avons mis en place une approche originale pour déterminer la distribution d'HbF à l’échelle cellulaire. En utilisant une cohorte longitudinale de patients traités par HC (inducteur d'HbF), nous avons montré que celui-ci avait un impact positif global sur les GR, en augmentant non seulement le contenu en HbF, mais également le volume de tous les GR, indépendamment de leur contenu en HbF. Nous avons par ailleurs montré que les cellules riches en HbF (High-F) étaient un marqueur précis d’efficacité de l'HC. Dans la dernière partie de la thèse, nous avons démontré pour la première fois une érythropoïèse inefficace chez les patients drépanocytaires et avons révélé un nouveau rôle de l'HbF au cours de l'érythropoïèse terminale, celui de protéger les érythroblastes de l'apoptose.En conclusion, ce travail montre que l'HbF a un effet bénéfique supplémentaire sur la drépanocytose en conférant non seulement une survie préférentielle des cellules F dans la circulation, mais en diminuant également l'érythropoïèse inefficace. Ce résultat suggère que la persistance d’HbF dans la drépanocytose serait davantage la conséquence d’un enrichissement en F-érythroblastes au cours de la différenciation érythroïde terminale survenant peu après la naissance plutôt qu’un retard du switch des hémoglobines
Sickle cell disease (SCD) is caused by a single point mutation in the β-globin gene generating sickle hemoglobin (HbS). Hypoxia drives HbS polymerization that is responsible for red blood cell (RBC) sickling and reduced deformability. In SCD, splenic dysfunction results in life-threatening complications, particularly in early childhood. During the course of the disease, the spleen functionally declines and anatomically disappears, although with great individual variability depending on modulating genetic and environmental factors. The key modulator of disease severity is fetal hemoglobin (HbF), as the presence of HbF inhibits HbS polymerization, thus delaying and preventing severe complications, ameliorating patients’ quality of life and increasing survival. There is a rather well characterized hetero cellular concentration of HbF and distribution in circulating RBCs but the role of HbF during erythropoiesis, is poorly documented. With the aim of better understanding the role of HbF in spleen function, red cell survival and ineffective erythropoiesis we investigated 1) the natural history of spleen dysfunction in SCD children, 2) the cellular expression and distribution of HbF in SCD children, in untreated patients and patients treated with Hydroxycarbamide and 3) ineffective erythropoiesis and the role of HbF during terminal erythropoiesis.We developed a flow cytometry high-throughput method to measure splenic filtration function and showed that splenic loss of function is present very early in life at 3-6 months in SCD children and further declines with age. We also highlighted that irreversibly sickled cells (ISCs) are a potential contributor to acute splenic sequestration (ASS) which in turn results in further loss of splenic function. In the second part of this work, we set up an original approach to determine HbF distribution per cell. Using a longitudinal cohort of patients treated with hydroxycarbamide (HC - an inducer of HbF), we showed that HC has a global positive impact on RBCs, by not only increasing HbF content but also by increasing the volume of all RBCs independent of HbF. We moreover showed that High F-cells are a more precise marker of HC efficacy. In the last part of the thesis, we showed for the first time clear evidence of ineffective erythropoiesis in SCD and revealed a new role of HbF during terminal erythropoiesis protecting erythroblasts from apoptosis. In conclusion, this work shows that HbF has an additional beneficial effect in SCD by not only conferring a preferential survival of F-cells in the circulation but also by decreasing ineffective erythropoiesis. Importantly, it suggests that the delay in hemoglobin switch in SCD might be also due to an enrichment in F-erythroblasts during terminal erythroid differentiation occurring very early in infancy, shortly after birth

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Jobling, Matthew S. « Fetal germ cell development in the rat testis and the impact of di (n-Butyl) phthalate exposure ». Thesis, University of Edinburgh, 2010. http://hdl.handle.net/1842/4803.

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During gonad development and fetal life, the germ cells (GC) undergo a range of different developmental processes necessary for correct postnatal gametogenesis and the production of the next generation. If these fetal events are disrupted by genetic or environmental factors, there could be severe consequences that may not present until adulthood. This is of particular importance in relation to human testicular GC tumours (TGCT), the most common cancer of young men, as TGCT is thought to arise from fetal GCs that have failed to differentiate normally during development and thus persist into adulthood, eventually becoming tumourigenic. TGCT is one of several related disorders of male reproductive health thought to comprise a Testicular Dysgenesis Syndrome (TDS), in which faulty testis development in fetal life may predispose to the development of cryptorchidism, hypospadias, reduced sperm count and TGCT. Currently there is no accepted animal model for TGCT, but some insight into human TDS has been gained through the use of a rat model using in utero Di (n-Butyl) Phthalate (DBP) exposure to induce cryptorchidism, hypospadias, low sperm count and reduced fertility (but not TGCT). However, a previous study suggested that DBP exposure can disrupt GC differentiation, resulting in significantly reduced GC number prior to birth and postnatal consequences. This thesis has been directed at investigating the normal process of GC development in the fetal rat and how this is altered by DBP exposure; such understanding may give insights into the origins of human TGCT by showing how and when disruption of normal fetal GC differentiation can occur. The first objective was to characterise GC development in both the rat testis and ovary to understand the normal events that occur between embryonic day (e)13.5 and e21.5, as most data in the literature is based on the mouse. Analysis by immunohistochemical, stereological and mRNA expression indentified that during this time period, a GC will undergo a dynamic sequence of changes involving migration, proliferation followed by differentiation (manifested by loss of specific protein markers), whilst undergoing germ-line specific remethylation. Whilst whole gonad development is vastly different between testes and ovaries, GC development was broadly the same with only minor differences up to the point where GCs in the ovary enter meiosis. Having established the normal process of GC development in the fetal rat testis, the effects of in utero DBP exposure was then investigated. DBP exposure reduced GC number at all ages investigated even after only 24 hours of exposure and simultaneously prolonged GC proliferation. As apoptosis was unaltered by DBP exposure, the consistent reduction in GC number was suggested to be due to an initial reduction in GC number that does not recover to control levels. GC differentiation was assessed by the expression and localization of specific protein markers (OCT4, DMRT1 and DAZL). The pattern of expression of OCT4 and DMRT1 was altered by DBP exposure. GCs in DBP exposed animals also showed a delay in disaggregation from within the centre of seminiferous cords. These results suggested that a delay in GC differentiation was occurring with DBP exposure. This delay in GC development persisted into early postnatal life, following cessation of DBP exposure. Thus at postnatal day (D)6, GC specific re-expression of DMRT1, GC migration to the basal lamina and resumption of GC proliferation all showed a delay. DBP also induced an increase in the presence of multinucleated gonocytes. DNA methylation in the fetal rat testis was also investigated as a mechanism that could be disrupted by DBP exposure. DNA methylation of GCs increased during the last week of fetal life by global methylation of the GC genome and the increased expression of DNA methyl transferases. No effect of DBP exposure was detected. Inhibition of methylation by 5-aza-2’deoxycytidine was then investigated as a way to block GC differentiation in fetal rat testes and this resulted in a similar transient delay in GC differentiation but was perinatally lethal to the fetus. Bisulphite sequencing of the OCT4 promoter was also performed but proved inconclusive. Methylation patterns may be being altered by DBP exposure, but such changes could not be identified in this thesis. To complement the in vivo DBP exposure studies, an in vitro testis explant system using e14.5 testes was investigated. These in vitro testis explants showed some GC effects with MBP, the active metabolite of DBP, and also suggested a novel role for Hedgehog signalling in GC survival in the fetal rat testis. The studies in this thesis have characterised several aspects of fetal GC development in the rat and identified which of these are affected by DBP exposure, resulting in a delay in GC development. As DBP exposure delays but does not block GC differentiation, this may explain why TGCT is not induced in the DBP exposure rat model for TDS.

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Gambero, Sheley. « Novos híbridos derivados de hidroxiureia e talidomida induzem a produção de hemoglobina fetal e apresentam atividade anti-inflamatória ». [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/309314.

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Orientador: Fernando Ferreira Costa
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas
Made available in DSpace on 2018-08-19T03:49:55Z (GMT). No. of bitstreams: 1 Gambero_Sheley_D.pdf: 3649073 bytes, checksum: a76d9a7da22f0e08a3f4556b9b24330f (MD5) Previous issue date: 2011
Resumo: A anemia falciforme (AF) é um distúrbio genético da hemoglobina causado por uma mutação de ponto no gene da beta-globina com consequente produção de hemoglobina S (HbS). A polimerização de HbS causa a deformação, enrijecimento e diminuição da flexibilidade das hemácias, resultando em uma série de eventos que levam a redução da sua vida média. Os principais fatores que influenciam a polimerização são: concentração de oxigênio e concentração de hemoglobina fetal (HbF). Pacientes com AF apresentam aumento dos níveis circulantes de citocinas, incluindo fator de necrose tumoral-'alfa' (TNF-'alfa') que possui efeitos pró-inflamatórios resultando no aumento das propriedades quimiotáxicas e a aderência de neutrófilos ao endotélio vascular. Muitos estudos têm sido realizados com o intuito de buscar novas estratégias terapêuticas que contribuam para o aumento dos níveis de HbF e diminuam os níveis de citocinas inflamatórias. Com este objetivo, novos compostos que agregam funções anti-inflamatórias e são moléculas doadoras de óxido nítrico, foram desenvolvidas. Deste modo, o objetivo deste trabalho foi avaliar os efeitos dos compostos derivados da hidroxiureia e da talidomida na produção de HbF, na atividade quimiotática e na produção de espécies reativas de oxigênio em células de pacientes com anemia falciforme e indivíduos controles, tratadas com o composto denominado Lapdesf 1, assim como a concentração de citocinas inflamatórias, em culturas de células mononucleares de camundongos falciforme. Os resultados obtidos demonstram que o composto Lapdesf 1 foi capaz de aumentar os níveis de HbF em cultura de células CD34+ e em linhagem celular K562. Os neutrófilos de indivíduos controles e pacientes com AF, tratados com este composto apresentaram a capacidade quimiotática induzida por Il-8 significativamente reduzida em relação ao controle, e o tratamento com Lapdesf 1 não alterou a geração de espécies reativas de oxigênio em plaquetas, neutrófilos, eritrócitos e células mononucleares. O tratamento de camundongos transgênicos para a AF demonstrou a capacidade desse composto em aumentar os níveis de HbF, além de diminuir a quantidade de citocinas inflamatórias no sobrenadante de culturas de células mononucleares de camundongos. Em resumo nossos resultados sugerem que o composto Lapdesf 1, apresenta-se como uma nova alternativa terapêutica, pela capacidade de aumentar a síntese de HbF e diminuir os níveis de citocinas inflamatórias e seus efeitos, que merece ser testada como possível tratamento da anemia falciforme
Abstract: Sickle cell anemia is a genetic hemoglobin disorder caused by a point mutation that produces hemoglobin S (HbS). Polymerization of HbS causes deformation, stiffness and decreased flexibility of red blood cells, resulting in different events. The main factors influencing polymerization are: oxygen concentration and intracellular concentration of fetal hemoglobin (HbF). It has been reported that patients with sickle cell disease have increased circulating levels of cytokines, including tumor necrosis factor-'alfa' (TNF-'alfa') which has pro-inflammatory effects, resulting in increased chemotactic properties and adhesion of neutrophils to vascular endothelium. Many studies have been conducted in order to pursue new therapeutic strategies that increase fetal hemoglobin levels and lower levels of inflammatory cytokines. New compounds have been developed for the treatment of some sickle cell anemia symptoms. These compounds have several functions: they act as antiinflammatory agents, and donate nitric oxide. Thus the objectives of this study were to evaluate effects of compounds derived from hydroxyurea and thalidomide in the production of HbF, chemotactic activity and production of reactive oxygen species in cells from patients with sickle cell anemia and controls treated with the compound called Lapdesf1, and also the concentration of inflammatory cytokines in cultures of mononuclear cells from sickle cell mice. Our results demonstrate that the compound, Lapdesf 1, was able to increase levels of fetal hemoglobin in CD34+ cultured cells and K562 lineage cells. Neutrophils from control subjects and patients with sickle cell anemia had their chemotactic capacity significantly reduced following treatment with this compound; furthermore, the compound did not alter the generation of reactive oxygen species in platelets, neutrophils, red cells and mononuclear cells. Treatment of transgenic sickle cell anemia mice demonstrated the ability of the compound to increase fetal hemoglobin in vivo and reduce the amount of inflammatory cytokines such as TNF-'alfa', IL-8, IL-6 and IL- 1ß in the supernatant of cultures of mononuclear cells from sickle mice. In summary, our results suggest that the compound Lapdesf 1 has the ability to increase HbF synthesis and decrease the levels of inflammatory cytokines and their effects. So this compound may present promise as a new drug for the treatment of sickle cell disease, minimizing the clinical complications associated with this disease
Doutorado
Biologia Estrutural, Celular, Molecular e do Desenvolvimento
Doutor em Fisiopatologia Medica

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Nevalainen, Nina. « Effects of glial cell line-derived neurotrophic factor (GDNF) on mouse fetal ventral mesencephalic tissue ». Thesis, Mälardalen University, Department of Biology and Chemical Engineering, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-615.

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The symptoms of Parkinson's disease occur due to degeneration of dopamine neurons in substantia nigra. It has been demonstrated that glial cell line-derived neurotrophic factor (GDNF) is a potent neurotrophic factor when it comes to protect and enhance survival of dopamine neurons in animal models of Parkinson's disease. The aim of this study was to evaluate short- and long-term effects of GDNF on survival and nerve fiber outgrowth of dopamine cells and astrocytic migration in mouse fetal ventral mesencephalic (VM) tissue. Primary tissue cultures were made of mouse fetal VM tissue and evaluated at 7 and 21 days in vitro (DIV) in terms of dopaminergic nerve fiber outgrowth and astrocytic migration when developed with GDNF present, partially, or completely absent. The results revealed that VM tissue cultured in the absence of GDNF did not exhibit any significant differences in migration of astrocytes or dopaminergic nerve fiber outgrowth neither after 7 DIV nor after 21 DIV, when compared with tissue cultured with GDNF present. Migration of astrocytes and dopaminergic nerve fiber outgrowth reached longer distances when tissue was left to develop for 21 DIV in comparison with 7 DIV. In order to study the long-term effects of GDNF, mouse fetal dopaminergic tissue was transplanted into the ventricles of adult mice and evaluated after 6 months. No surviving dopamine neurons were present in the absence of GDNF. In contrast dopamine neurons developed with GDNF did survive, indicating that GDNF is an essential neurotrophic factor when it comes to long-term dopamine cell survival. More cases have to be assessed in the future in order to strengthen the findings. Thus, transplanted dopamine neurons will be assessed after 3 and 12 months in order to map out when dopamine neurons deprived of GDNF undergo degeneration.

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Yamada(Takahara), Sachiko. « Programmed cell death is not a necessary prerequisite for fusion of the fetal mouse palate ». Kyoto University, 2004. http://hdl.handle.net/2433/147567.

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Thèses sur le sujet « Fetal cell »

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