• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 44
  • 29
  • 2
  • 1
  • 1
  • Tagged with
  • 102
  • 22
  • 21
  • 15
  • 14
  • 14
  • 12
  • 11
  • 11
  • 10
  • 9
  • 9
  • 9
  • 9
  • 9
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Does maternal nicotine exposure during gestation and lactation change the oxidant-antioxidant status of the lungs of the offsprings and is tomato juice protecting the lungs of the offsprings?

Abdulkarim, Kayigire Xavier. January 2009 (has links)
<p>Nicotine exposure to the fetus through tobacco smoking or nicotine replacement therapy during the whole period of gestation and lactation causes diverse effects on fetal and neonatal lung development, integrity and maturation which compromise the gas exchange function of the lungs and renders this vital organ susceptible to gradual damage and different diseases in latter life. Maternal nicotine exposure during gestation and lactation results in gradual destruction of the lung parenchyma, and this leads to the combination of many small air sacs in one bigger alveoli which is a sign of emphysema. Many researchers speculated that the way in which, nicotine causes emphysema and other damage, is by inducing the formation of many reactive oxygen species (ROS), and creating an imbalance between the oxidants and the antioxidants of the body, which is termed oxidative stress. The aim of this study was to assess the effects of nicotine exposure on the lung of the fetal and neonate rat during gestation and lactation as gas exchanger, and also to see whether the supplementation of tomato juice containing lycopene, a powerful carotenoid antioxidant could protect the lungs against these effects of maternal nicotine exposure. In this study pregnant rats have been divided into 4 groups: a group which received nicotine (1mg/kg body weight/day) subcutaneously, a group that received the tomato juice only (6mg/kg body weight/day per os), a third group that received the combination of tomato juice ( 6mg /kg body weight/ day per os) and nicotine (1mg/kg body weight /day subcutaneously ) . The control group that received saline (1mg/kg body weight /day) subcutaneously and water. The injections were done during pregnancy and lactation until weaning at postnatal day 21. The results showed that maternal nicotine exposure during gestation and lactation leads to a gradual damage of the lung parenchyma and slower formation of the alveoli during the equilibrated phase of the lung growth leading to a decrease in the internal surface area required for gas exchange. Supplementation with tomato juice during gestation and lactation prevents all the adverse effects of maternal nicotine exposure on the lungs of the offspring. Since nicotine induce an increase in the oxidant levels of the mother and the fetus, my results imply that lycopene protected the lungs of the offsprings against the oxidants and thus against changes in the program that controls lung development as the animals age. This is supported by the observation that at postnatal day 84 the antioxidant.</p>
42

The antenatal management of the twin fetus from 30 weeks gestation.

January 1979 (has links)
Thesis (M.D.)-University of Natal, Durban, 1979.
43

Mechanisms of DNA methylation defects at the IGF2/H19 imprinting centre in patients with foetal growth disorders

Shmela, Mansur Ennuri, S3149770@student.rmit.edu.au January 2009 (has links)
The imprinted expression of the IGF2 and H19 genes is controlled by the imprinting control region 1 (ICR1) located at chromosome 11p15.5. This methylation-sensitive chromatin insulator works by binding the zinc-finger protein CTCF in a parent-specific manner. CTCF binds the unmethylated maternal allele and is required for preventing de novo methylation at ICR1. DNA methylation defects involving the ICR1 IGF2/H19 domain result in two growth disorders with opposite phenotypes: an overgrowth disorder, the Beckwith-Wiedemann syndrome (ICR1 gain of methylation in 10% of BWS cases) and a growth retardation disorder, the Silver-Russell syndrome (ICR1 loss of methylation in 60% of SRS cases). Little information is available regarding the mechanism of ICR1 DNA methylation defects. Several deletions removing part of ICR1 (1.4 to 2.2 kb) have been described in a few familial BWS cases with dominant maternal transmission. In order to evaluate precisely the incidence of ICR1 mutations, we investigated, by long range PCR and sequencing, 21 BWS patients (including two brothers) with ICR1 gain of methylation and 16 SRS patients with ICR1 loss of methylation. No mutation of the seven CTCF binding sites was detected in the familial BWS cases. Two additional cases of constitutional genetic lesions were identified in BWS patients with apparently-sporadic forms. One patient was identified with a 8 bp deletion within the B3 repeat, 116 bases 3' of the CTCF binding site 4. Another patient was identified with a 1.8 kb deletion which eliminates CTCF binding sites 2 and 3. A single-nucleotide variation was identified in a SRS patient. Our data showed that ICR1 deletions, including new small deletions, account for apparently sporadic forms of BWS with ICR1 gain of methylation. ICR1 deletions are associated with a high incidence of Wilms' tumour, making their molecular diagnosis particularly important for genetic counseling and tumor surveillance.
44

Comparative aspects on genetics of stillbirth and calving difficulty in Swedish dairy cattle breeds /

Steinbock, Lena, January 2006 (has links) (PDF)
Licentiatavhandling Uppsala : Sveriges lantbruksuniversitet, 2006. / Härtill 2 uppsatser.
45

Analyse, caractérisation et classification de signaux foetaux / Analysis, characterization and classification of fetal signals

Voicu, Iulian 13 December 2011 (has links)
L’objectif de ce travail est d’obtenir, grâce à un mélange de différentes informations, un monitorage de l’activité du fœtus pour apprécier son état de bien-être ou de souffrance.Actuellement, les paramètres qui caractérisent la souffrance fœtale, issus du rythme cardiaque et des mouvements fœtaux, sont évalués par le médecin et ils sont réunis dans le score de Manning. Deux inconvénients majeurs existent: a) l’évaluation du score est trop longue puisqu’elle dure 1 heure b) il existe des variations inter et intra-opérateur conduisant à différentes interprétations du bilan médical de la patiente.Pour s’affranchir de ces désavantages nous évaluons le bien-être fœtal d’une façon objective, à travers le calcul d’un score. Pour atteindre ce but, nous avons développé une technologie ultrasonore mufti-capteurs permettant de recueillir une soixantaine de signaux Doppler en provenance du cœur, des membres inférieurs et supérieurs. / The objective of this work is to assess the fetal parameters and the fetal well-being using a mixture of fetal parameters. In our days, the parameters derived from heart rate and fetal movements that characterize the fetal distress are assessed by the physician and unified in the score of Manning. Two major disadvantages of Manning’s score exist: a) the assessment of the score is time consuming; b) there are variations inter and intra operators leading to different interpretations of the patients medical record. To overcome these disadvantages we assess the fetal well-being objectively, by computing an automatic/electronic score. To achieve this goal, we developed an ultrasonic multi-sensor unit with 12 sensors allowing to collect sixty Doppler signals from the heart, lower and upper limbs.
46

Analysing the spontaneous speech of children with Foetal Alcohol Spectrum Disorder (FASD)

Martin, Linique January 2016 (has links)
Magister Artium - MA / Foetal Alcohol Spectrum Disorder (FASD) is a global problem that affects various communities. FASD denotes a pattern of abnormalities intermittently seen in children born to women who consume huge quantities of alcohol during pregnancy (Church & Kaltenbach, 1997). Church and Kaltenbach (1997) suggest that FAS may be one of the primary causes of hearing, speech and other language problems in children. The two main approaches used to determine the effects of FASD on language are standardised language test (using a statistical approach to test some or all four domains of language, namely, phonology, syntax, morphology and semantics) applied to close-ended questionnaire answers and, to some extent, narrative analysis (in the course of which researchers use wordless picture books to analyse narratives in order to determine the social-communicative characteristics of individuals with FASD). Although the use of standardized measures of language might be helpful to determine problematic areas in relation to the different language domains (Wyper & Rasmussen, 2011), they do not show the difficulty with social-communicative functions which these children might be facing (Coggins, Friet, & Morgan, 1998). On the other hand, while narrative analysis addresses an important level of language (discourse level), it does not foreground the inherently interactive nature of language use and the problems that may be associated with communicative interactions. These shortcomings, in turn, suggest possible limitations in the interventions intended to address the language needs of children with FASD. There is, therefore, a need for complementary approaches that offer a more rounded picture of language impairment in children with FASD. In this study, three approaches are used in identifying features of the speech of children with FASD against the backdrop of comparisons with features in the speech of normally developing children. Firstly, conversational analysis (applied to spontaneous, open-ended speech) is introduced as a means to determine the more social-interactive aspects of speech impairment in children with FASD. Secondly, measures of linguistic aspects of speech (the mean length of utterance, Index of Productive Syntax and the number of different word roots) designed specifically for spontaneous speech are employed (they are applied to the same spontaneous data as the conversational analysis data). Thirdly, the more traditional standardized language test measures applied to non-spontaneous speech are used (covering the four domains of syntax, phonology, semantics, and pragmatics). The study’s objectives are to (1) compare patterns in the interactive speech of FASD children and normally developing children; (2) explore the relationship between FASD children and normally developing children in relation to both spontaneous speech measures and standardized measures of language; and (3) compare the impact of the primary caregiver's level of education on testing through spontaneous measures versus standardised measures. Using data from 14 children in the Bellville suburb of Cape Town, South Africa, the study finds that, on the conversational analysis measures, children with FASD, in contrast to normally developing children, tend to obey fewer rules of turn-taking, to overlap less, to engage less in self-repair and to struggle with management and maintenance of topics. The study also finds that children whose scores on the standardized language tests (with non-spontaneous data) suggest they have no language difficulty, especially in terms of phonology, obtained scores in measures of spontaneous speech that indicated language difficulty. The study also found that the socio-economic status of caregivers was a credible explanation for certain features in the speech of children with FASD is very similar to features in the speech of normally developing children. This finding highlights the role of family setting in mitigating the effects of FASD. / National Research Foundation (NRF)
47

Does maternal nicotine exposure during gestation and lactation change the oxidant-antioxidant status of the lungs of the offsprings and is tomato juice protecting the lungs of the offsprings?

Abdulkarim, Kayigire Xavier January 2009 (has links)
Magister Scientiae (Medical Bioscience) - MSc(MBS) / Nicotine exposure to the fetus through tobacco smoking or nicotine replacement therapy during the whole period of gestation and lactation causes diverse effects on fetal and neonatal lung development, integrity and maturation which compromise the gas exchange function of the lungs and renders this vital organ susceptible to gradual damage and different diseases in latter life. Maternal nicotine exposure during gestation and lactation results in gradual destruction of the lung parenchyma, and this leads to the combination of many small air sacs in one bigger alveoli which is a sign of emphysema. Many researchers speculated that the way in which, nicotine causes emphysema and other damage, is by inducing the formation of many reactive oxygen species (ROS), and creating an imbalance between the oxidants and the antioxidants of the body, which is termed oxidative stress. The aim of this study was to assess the effects of nicotine exposure on the lung of the fetal and neonate rat during gestation and lactation as gas exchanger, and also to see whether the supplementation of tomato juice containing lycopene, a powerful carotenoid antioxidant could protect the lungs against these effects of maternal nicotine exposure. In this study pregnant rats have been divided into 4 groups: a group which received nicotine (1mg/kg body weight/day) subcutaneously, a group that received the tomato juice only (6mg/kg body weight/day per os), a third group that received the combination of tomato juice ( 6mg /kg body weight/ day per os) and nicotine (1mg/kg body weight /day subcutaneously ) . The control group that received saline (1mg/kg body weight /day) subcutaneously and water. The injections were done during pregnancy and lactation until weaning at postnatal day 21. The results showed that maternal nicotine exposure during gestation and lactation leads to a gradual damage of the lung parenchyma and slower formation of the alveoli during the equilibrated phase of the lung growth leading to a decrease in the internal surface area required for gas exchange. Supplementation with tomato juice during gestation and lactation prevents all the adverse effects of maternal nicotine exposure on the lungs of the offspring. Since nicotine induce an increase in the oxidant levels of the mother and the fetus, my results imply that lycopene protected the lungs of the offsprings against the oxidants and thus against changes in the program that controls lung development as the animals age. This is supported by the observation that at postnatal day 84 the antioxidant. / South Africa
48

Altération de la croissance fœtale et programmation métabolique : étude de l’implication des Rho-kinases et du système apelinergique chez les rongeurs / Intrauterine growth disturbance and metabolic programming : implication of the Rho-kinase pathway and of the apelinergic system in rodents

Butruille, Laura 26 September 2013 (has links)
Durant ces dernières années, de nombreuses études épidémiologiques ont mis en évidence que les pathologies métaboliques (obésité, diabète) et cardiovasculaires pourraient, en partie, se déterminer dès la grossesse, via des perturbations de l’environnement intra-utérin. La notion de « programmation fœtale » implique qu’une altération durant la vie fœtale perturberait le développement du fœtus et le vulnérabiliserait au développement ultérieur de pathologies. Ainsi, un enfant qui naît avec un très faible poids de naissance (inférieur à 2,4 kg) ou à l’inverse avec un poids de naissance très élevé (supérieur à 4,0 kg) est statistiquement plus vulnérable au développement de ces maladies. Pour étudier ce phénomène et tenter d’en comprendre les mécanismes, nous avons utilisé des modèles expérimentaux (rat, souris) et évalué l’action et l’expression de deux substances vasodilatatrices : le Fasudil (un inhibiteur des Rho kinases) et l’hormone apeline. Les rates gestantes traitées par le L-NAME, un inhibiteur de la NO synthase (50 mg/jour) présentaient une hypertension artérielle et leurs nouveau-nés un retard de croissance intra-utérin (RCIU) de l’ordre de 20%. L’administration aux mères de Fasudil (10 mg/jour) permettait de restaurer une pression artérielle normale en fin de gestation et améliorait considérablement la croissance fœtale des animaux exposés au L-NAME. Cependant, alors que les animaux nés avec un RCIU (nouveau-nés L-NAME) ne présentaient que peu de perturbations métaboliques à l’âge adulte, les animaux exposés au Fasudil seul étaient rapidement en surpoids, présentaient une hyperglycémie à jeun et développaient des troubles du comportement alimentaire de type hyperphagique. D’autre part, par une étude menée chez des souris obèses et intolérantes au glucose après exposition à un régime hyperlipidique, nous avons démontré que l’expression génique de l’apeline est altérée dans plusieurs organes (foie, rein, tissu adipeux) bien que l’apelinémie des souris obèses reste inchangée. Des études en voie de finalisation sont menées afin de déterminer si le système apelinergique est modulé chez des souris gestantes obèses à la fois chez les compartiments maternels et fœtaux mais aussi dans le placenta. En conclusion, nous avons démontré que l’inhibition de la voie des Rho kinases en fin de gestation programme chez la descendance un surpoids, une hyperglycémie et à une altération de la prise alimentaire. Ayant démontré que le système apelinergique est altéré chez des souris femelles obèses et intolérantes au glucose, il nous reste à déterminer si ce système est aussi perturbé en condition de grossesse associée à l’obésité maternelle. / During the last decade, many epidemiological studies have shown that adult chronic metabolic (obesity, diabetes) and cardiovascular diseases may be determined, at least in part, during pregnancy through alterations of intrauterine environment. The “fetal programming” hypothesis implies that disturbances of the fetal development (intra uterine growth restriction – IUGR or macrosomia) increase the vulnerability to develop these pathologies in adulthood. To gain more insight into the mechanisms implicated in fetal programming, we used two experimental models of rodents (rat, mouse) and evaluated first the effect of an inhibition of the Rho-kinase pathway in utero on fetal growth and postnatal development in rats. In another study performed in mice, we aimed to assess the expression of apelin and its receptor APJ in obese and glucose intolerant mice fed with a high fat diet. Using data of this preliminary study, we speculated that this signaling system may be targeted during the pregnancy of obese mothers and could be implicated into the physiopathological consequences that may affect the fetoplacental unit. We demonstrated that pregnant rats treated by L-NAME, a NO synthase inhibitor (50 mg/day) were hypertensive and that their newborns presented a dramatic IUGR. Maternal treatment with the vasodilator Fasudil (10 mg/day) restored a normal maternal blood pressure and remarkably alleviated the fetal growth of L-NAME newborns. In adults, L-NAME male rats developed mild metabolic pathologies whereas rats exposed in utero to Fasudil presented an overweight, with hyperphagia and glucose intolerance. In obese and glucose intolerant mice fed with a high fat diet, we showed that apelin gene expression was altered in several organs (liver, kidney and adipose tissue) without any variation of apelin plasma concentration. Further studies are currently performed in our laboratory to unravel the expression of the apelin/APJ pathway in pregnant obese mice and their offsprings.
49

Prolactine placentaire et anomalies de croissance au cours du diabète maternel / Placental prolactin and growth disorders during maternal diabetes

Perimenis, Pierrette 20 September 2014 (has links)
Malgré l’amélioration des prises en charge diabétologiques et obstétricales, la grossesse chez la patiente ayant un diabète pré-gestationnel ou gestationnel reste à ce jour à haut risque pour la mère et pour l’enfant. Chez l’enfant, les anomalies de croissance, macrosomie, mais parfois Retard de Croissance Intra-Utérin (RCIU) restent à ce jour très fréquentes avec des conséquences à court et à long terme. La croissance fœtale est un processus complexe mettant en jeu la susceptibilité génétique fœtale mais surtout le milieu intra-utérin à savoir l’environnement métabolique maternel et placentaire. Les mécanismes physiopathologiques en lien avec ces anomalies de croissance dans ce contexte de diabète restent encore incompris et mal expliqués par l’hyperglycémie maternelle seule. A l’interface entre la mère et le fœtus, le placenta exerce plusieurs fonctions influençant le métabolisme maternel et fœto-placentaire donc le développement de l’unité fœto-placentaire. Le placenta, acteur crucial de la programmation fœtale, va s’adapter à son environnement afin de permettre la survie fœtale.L’objectif de ce travail de thèse était d’étudier le compartiment placentaire en analysant l’expression des gènes impliqués dans la croissance fœto-placentaire afin de déterminer des facteurs prédictifs des anomalies de croissance au cours du diabète maternel. Pour répondre à cet objectif, nous avons d'abord utilisé un modèle de rate gestante rendue diabétique par la streptozotocine seule ou associée avec la nicotinamide et validé certains de nos résultats dans des placentas issus de patientes diabétiques de type 1. L’analyse du transcriptome placentaire a mis en évidence l’implication prépondérante de certains gènes appartenant à la famille prolactine (PRL), au système rénine-angiotensine et aux métalloprotéases. La caractéristique phénotypique de ces ratons était de présenter un RCIU à la naissance avec sur le plan histologique une hypovascularisation placentaire associée.Nous nous sommes surtout intéressés aux gènes placentaires appartenant à la famille PRL, non décrits auparavant dans la littérature dans le diabète, comme prl8a2, connu aussi sous le nom de Dprp (Decidual Prolactin Related-Protein). La PRL dans sa forme native de 23-kDa a des propriétés pro-angiogéniques alors que clivée en vasoinhibines par la Bone morphogenetic protein1 (BMP1), la cathepsine D, a des propriétés anti-angiogéniques. Chez nos 2 modèles de rates, nous confirmons une surexpression par qPCR de Dprp, et de Bmp1 et une augmentation du rapport du clivage de la PRL et donc des vasoinhibines par rapport aux contrôles.Nous avons pu valider ces résultats dans des placentas de patientes diabétiques de type 1 dont la caractéristique chez les nouveaux nés était un petit poids de naissance. Enfin, nous nous sommes intéressés à la cinétique de ces anomalies concernant la famille PRL dans nos modèles animaux. Nous avons pu montrer chez la rate gestante diabétique que le RCIU était présent dès le 14ème jour de gestation et que la quantité en vasoinhibines et l’expression des gènes Bmp1 et Dprp n'étaient modifiées qu'à partir du 17ème jour de gestation.Ces travaux sont en faveur d’une implication de la PRL placentaire et de ses vasoinhibines dans le diabète maternel laissant leur supposer un rôle dans l’hypovascularisation placentaire, mise en évidence à la fois chez l'homme et l'animal. En perspective, nous envisageons de poursuivre ces travaux avec une approche plus fonctionnelle. Il convient de préciser l’implication de la BMP1 en confirmant sa responsabilité dans le clivage de la PRL, en analysant plus finement la relation entre vasoinhibines et hyperglycémie en tenant compte du degré et de la durée d’exposition de l'hyperglycémie. Enfin, il serait intéressant de regarder l’implication de la PRL placentaire non plus au cours du RCIU mais plutôt au cours de la macrosomie fœtale, qui reste l’anomalie de croissance la plus fréquente au cours du diabète maternel. / Despite the improvement of obstetrical and diabetological care, the pregnancy of the patient presenting a gestational or pregestational diabetes remains ourdays at a high risk for the mother and for its child. For the child, fetal growth disorders such as macrosomia but also intra-uterine growth restriction (IUGR) are still very frequent with short and long-term consequences. Fetal growth is a complex process involving the fetal genetic susceptibility but also the intra-uterine environment especially in its maternal and placental metabolic aspects. The link between the physiopathological mechanisms of these disorders and fetal growth in this context of maternal diabetes remains unclear and partially explained by maternal hyperglycemia only. At an interface between the mother and the fetus, the placenta employes multiples functions that influence maternal, fetal and placental metabolisms and consequently the fetoplacental unit development. The placenta, as crucial actor of fetal programming, must adapt to its environnment for the survival of the fetus.The objectives of this thesis were to study the placental compartment with an analysis of expression of genes involved in feto-placental growth to determine the predictive factors of these growth disorders during maternal diabetes. To bring a response to these objectives, we used initially a model of gestant rat diabetes induced by streptozotocin alone or in combination with nicotinamide and we validated some of our results in the placenta from type 1 diabetic mothers.The placental transcriptomic analysis pointed out the involvment of some genes of the prolactin (PRL) family, of the renine-angiotensin-aldosterone system and of metalloproteinase family. The principal phenotypical characteristic of the pups at birth was an IUGR with an histological aspect of a placental hypovascularization associated.We focused especially to the placental genes of the PRL familly, non described before in the litterature in diabetes, such as prl8a2 also known as Dprp (decidual prolactin related-protein). PRL in its native form of 23 kDa is proangiogenic but when processed by Bone morphogenetic protein 1 (BMP-1) or cathepsin D (CTSD) to vasoinhibins has antiangiogenic properties. In our 2 rat models, we demonstrated by qPCR an upregulation of Bmp-1 and Dprp with an increase amount of vasoinhibins when compared to controls.We could validate some of our results in the placenta from diabetic type 1 women with a characteristic of small birth weight of the newborns.Finally, we interested in the course of these disorders concerning PRL family in our animal models during their pregnancy. We could demonstrate that IUGR was present by 14th day of gestation. Bmp-1 or Dprp gene expression and the vasoinhibin amount were not different between groups at the 14th day of gestation but modified by 17th day of gestation.These studies highlighted a placental involvment of PRL and its vasoinhibins during maternal diabetes suggesting a role in placental hypovascularisation in animal and women.The perspectives will be in continuing these studies with a more functional approach. We have to bring more details about the involvment of BMP-1 in this PRL process with an in-depth analysis of the link between hyperglycemia and vasoinhibins among the degree and the time of exposition to hyperglycemia. Finally, it would be interesting to study the involvment of placental PRL not only in the cases of IUGR but also in that of macrosomia, that remains the most frequent fetal growth disorder during maternal diabetes.
50

Placental sonic hedgehog pathway regulates foetal growth via insulin-like growth factor axis in preeclampsia / 妊娠高血圧腎症では胎盤におけるソニックヘッジホッグ経路がインスリン様成長因子系を介して胎児発育を制御する

Takai, Hiroshi 25 May 2020 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22640号 / 医博第4623号 / 新制||医||1044(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 近藤 玄, 教授 斎藤 通紀, 教授 篠原 隆司 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Page generated in 0.058 seconds